use std::collections::{HashMap, HashSet};
use std::ops::Sub;
use crate::navigator::Navigator;
use crate::rdf::term_helper::{TermHelper, TermHelperMut};
use crate::widget::iri_input::iri_input;
use crate::widget::navigation_area::navigation_area;
use gl_graph::{language, CurieHelper, vocab};
use gl_search::{Schema, SearchIndex};
use http::StatusCode;
use iced::alignment::Horizontal;
use iced::keyboard::{Event, key};
use iced::widget::button::Style;
use iced::widget::{button, center, column, combo_box, container, grid, mouse_area, opaque, operation, pick_list, row, scrollable, space, stack, table, text, text_input, toggler};
use iced::window::Settings;
use iced::{Background, Color, Element, Length, Subscription, Task, color, keyboard, window};
use iced::advanced::text::Wrapping;
use iced::widget::grid::Sizing;
use ldp::middleware::BasicAuthMiddleware;
use ldp::model::{KeyedDataset, QuadKey};
use ldp::reqwest::{Client, Url};
use ldp::reqwest_middleware::{ClientBuilder, ClientWithMiddleware};
use ldp::{RdfSource, RdfSourceUpdateResponse, ResourceRequestBuilder, SerializationOptions};
use oxigraph::io::RdfFormat;
use oxigraph::model::{BaseDirection, Graph, NamedNode, NamedOrBlankNode, NamedOrBlankNodeRef, Quad, Term, TermRef, Triple, TripleRef};
use tracing::{error, trace};
use gl_graph::class::Class;
use gl_graph::ontology::{ConnectedOntology, OntologyBuilder, ReadOnlyEntity, ResourceDescription};
use gl_search::tantivy::schema::Value;
use crate::rdf::conversion::term_to_named_node;
use crate::tasks;

#[derive(Clone, Debug)]
pub(crate) enum Message {
    None,
    ConnectToOntologyService(String),
    ConnectedToOntologyService(ConnectedOntology),
    CacheDatatypes(HashMap<NamedNode, ResourceDescription>),
    CacheReadOnlyEntities(HashSet<ReadOnlyEntity>),
    PopulateCaches,
    LookupResourceDescriptions(HashSet<NamedNode>),
    CacheResourceDescriptions(HashMap<NamedNode, ResourceDescription>),
    WindowClosed(window::Id),
    URLInputChanged(String),
    URLInputSubmitted,
    NavigateTo(Url),
    FetchDocument(Url),
    LoadDocument(RdfSource<KeyedDataset<RowState>>),
    ResourceNotFound,
    ShowNewDocumentButtons,
    HideNewDocumentButtons,
    ShowError(String),
    AddRow(Option<(QuadKey, RowState)>),
    DeleteRow(QuadKey),
    OpenQueryWindow(SearchResultClickAction),
    HoverRow(QuadKey),
    UnhoverRow(QuadKey),
    QueryUpdated(String),
    SetSearchResults(Vec<HashMap<gl_search::Field, gl_search::OwnedValue>>),
    UpdateQueryClass(Class),
    SearchResultClicked(NamedNode),
    DatatypeUpdated(QuadKey, Option<String>),
    LanguageUpdated(QuadKey, Option<String>),
    SubjectUpdated(QuadKey, String),
    PredicateUpdated(QuadKey, String),
    ObjectUpdated(QuadKey, String),
    DirectionToggled(QuadKey, BaseDirection),
    SaveGraph(bool),
    ShowOverwriteConfirmationModal,
    HideOverwriteConfirmationModal,
    ConfirmOverwrite,
    NewDocument(Class, Option<Url>),
    NavigateToPredicate(QuadKey),
    NavigateToObject(QuadKey),
    NavigateBack,
    NavigateForward,
    ResetState,
    SetShowReadOnly(bool),
    SetShowInferredTriples(bool),
    RunInference,
    SetInferredTriples(Graph),
    Event(Event),
}

#[derive(Default, Debug, Clone)]
pub(crate) struct RowState {
    read_only: bool,
    datatype_state: combo_box::State<String>,
}

#[derive(Debug, Clone)]
pub(crate) enum SearchResultClickAction {
    URLInput,
    Predicate(QuadKey),
    Object(QuadKey),
}

struct SearchState {
    window_id: window::Id,
    action: SearchResultClickAction,
    entity_class_selection: Option<Class>,
    query: String,
    results: Vec<HashMap<gl_search::Field, gl_search::OwnedValue>>,
}

pub(crate) struct Publisher {
    http_client: ClientWithMiddleware,
    curie_helper: CurieHelper,
    ontology: Option<ConnectedOntology>,
    read_only_entities: HashSet<ReadOnlyEntity>,
    abbreviated_datatypes: Vec<String>,
    resource_descriptions: HashMap<NamedNode, ResourceDescription>,
    window_id: window::Id,
    url_input: String,
    url_input_valid: bool,
    navigator: Navigator<Url>,
    document: RdfSource<KeyedDataset<RowState>>,
    inferred_triples: Graph,
    show_read_only: bool,
    show_inferred_triples: bool,
    hovered_row: Option<QuadKey>,
    search_state: Option<SearchState>,
    index: SearchIndex,
    show_overwrite_confirmation: bool,
    modified: bool,
    show_new_document_buttons: bool,
    resource_not_found: bool,
}

impl Publisher {
    fn is_read_only<'a>(&'a self, triple: impl Into<TripleRef<'a>>) -> bool {
        let triple = triple.into();
        if triple.predicate == vocab::rdf::TYPE &&
            let TermRef::NamedNode(node) = triple.object {
            self.read_only_entities.contains(&ReadOnlyEntity::Class(node.into_owned()))
        } else {
            self.read_only_entities.contains(&ReadOnlyEntity::Property(triple.predicate.into_owned()))
        }
    }

    pub(crate) fn new() -> (Self, Task<Message>) {
        let curie_helper = CurieHelper::new(gl_graph::PREFIXES.clone());

        let index = SearchIndex::builder()
            .with_path("/home/alex/.local/share/org.graphofliberty.desktop/index")
            .build()
            .expect("Failed to build search index");

        let (id, task) = window::open(Settings::default());

        let client = Client::new();
        let http_client = ClientBuilder::new(client.clone())
            .with(BasicAuthMiddleware::new(
                "fedoraAdmin".to_string(),
                Some("fedoraAdmin".to_string()),
            ))
            .build();

        let starting_url = Url::parse("http://fedora.quill.lan/rest/").unwrap();
        let navigator = Navigator::new(starting_url.clone());
        let document = RdfSource::new(starting_url.clone());

        (
            Self {
                http_client,
                curie_helper,
                ontology: None,
                read_only_entities: HashSet::new(),
                abbreviated_datatypes: Vec::new(),
                resource_descriptions: HashMap::new(),
                window_id: id,
                url_input: starting_url.to_string(),
                url_input_valid: true,
                navigator,
                document,
                inferred_triples: Graph::new(),
                show_read_only: false,
                show_inferred_triples: false,
                hovered_row: None,
                search_state: None,
                index,
                show_overwrite_confirmation: false,
                modified: false,
                show_new_document_buttons: false,
                resource_not_found: false,
            },
            task.map(|_| Message::ConnectToOntologyService("http://[::1]:3000".to_string())),
        )
    }

    pub(crate) fn update(&mut self, message: Message) -> Task<Message> {
        let mut task = Task::none();
        trace!(?message);

        match message {
            Message::ConnectToOntologyService(endpoint) => {
                let builder = OntologyBuilder::from_string(&endpoint, language::ENGLISH_OR_UNTAGGED.clone())
                    .expect("Unable to parse endpoint of ontology service");

                task = tasks::connect_to_ontology_service(builder)
                    .chain(Task::done(Message::PopulateCaches));
            }
            Message::ConnectedToOntologyService(ontology) => {
                self.ontology = Some(ontology);
            }
            Message::PopulateCaches => {
                if let Some(ontology) = &mut self.ontology {
                    let classes = Class::ALL.iter().map(|class| {
                        class.to_named_node().into_owned()
                    });

                    task = Task::batch([
                        tasks::list_datatypes(ontology.clone()),
                        tasks::list_read_only_entities(ontology.clone()),
                        tasks::lookup_resource_descriptions(ontology.clone(), classes),
                    ])
                }
            }
            Message::CacheDatatypes(datatypes) => {
                self.abbreviated_datatypes = datatypes.keys()
                    .map(|node| {
                        self.curie_helper.abbreviate(None, node.as_str())
                            .unwrap_or(node.as_str().to_string())
                    }).collect();
            }
            Message::CacheReadOnlyEntities(entities) => {
                self.read_only_entities = entities;
            }
            Message::LookupResourceDescriptions(nodes) => {
                let provided_nodes: HashSet<NamedNode> = HashSet::from_iter(nodes);
                let nodes_with_known_descriptions = HashSet::from_iter(self.resource_descriptions.keys().cloned());
                let nodes_to_look_up = provided_nodes.sub(&nodes_with_known_descriptions);

                if let Some(ontology) = &mut self.ontology {
                    task = tasks::lookup_resource_descriptions(ontology.clone(), nodes_to_look_up)
                }
            }
            Message::CacheResourceDescriptions(descriptions) => {
                self.resource_descriptions.extend(descriptions);
            }
            Message::WindowClosed(id) => {
                if self.window_id == id {
                    task = iced::exit();
                } else {
                    self.search_state = None;
                }
            }
            Message::URLInputChanged(value) => {
                self.url_input_valid = Url::parse(&value).is_ok();
                self.url_input = value;
            }
            Message::URLInputSubmitted => {
                if let Ok(url) = Url::parse(&self.url_input) {
                    if &url != self.navigator.current() {
                        self.navigator.goto(url.clone());
                    }
                    task = Task::done(Message::NavigateTo(url));
                }
            }
            Message::NavigateTo(url) => {
                task = Task::done(Message::ResetState)
                    .chain(Task::done(Message::FetchDocument(url)));
            }
            Message::FetchDocument(url) => {
                let client = self.http_client.clone();
                task = Task::future(async {
                    let request = ResourceRequestBuilder::with_client_and_url(client, url)
                        .accept_rdf_format(RdfFormat::Turtle)
                        .follow_described_by(true)
                        .build();

                    match request.send().await {
                        Ok(resource) => match resource.into_rdf_source().await {
                            Ok(rdf_source) => Message::LoadDocument(rdf_source),
                            Err(err) => {
                                Message::ShowError(format!("Unable to parse response: {err}"))
                            }
                        },
                        Err(ldp::Error::Reqwest(err)) => {
                            if err.status() == Some(StatusCode::NOT_FOUND) {
                                Message::ResourceNotFound
                            } else {
                                Message::ShowError(err.to_string())
                            }
                        }
                        Err(err) => Message::ShowError(format!("Request failed: {err}")),
                    }
                });
            }
            Message::ResourceNotFound => {
                self.resource_not_found = true;
                task = Task::done(Message::ShowNewDocumentButtons);
            }
            Message::LoadDocument(document) => {
                let nodes_to_look_up = document.dataset().quads.iter().flat_map(|(_, quad)| {
                    let mut nodes = vec![ quad.predicate.clone() ];
                    if let Some(object) = term_to_named_node(&quad.object) {
                        nodes.push(object.clone());
                    }
                    nodes
                }).collect();

                let add_row_tasks = document.dataset().quads.iter().map(|(key, quad)| {
                    let datatype_state = combo_box::State::new(self.abbreviated_datatypes.clone());
                    let state = RowState {
                        read_only: self.is_read_only(quad.as_ref()),
                        datatype_state,
                    };
                    Task::done(Message::AddRow(Some((key, state))))
                });
                task = Task::done(Message::LookupResourceDescriptions(nodes_to_look_up))
                    .chain(Task::batch(add_row_tasks))
                    .chain(Task::done(Message::RunInference))
                    .chain(Task::done(Message::ResetState));

                self.document = document;
            }
            Message::ShowError(error) => {
                error!(error);
            }
            Message::AddRow(None) => {
                let mut quad = self.document.new_quad();
                let empty_node = NamedNode::new_unchecked("");
                quad.predicate = empty_node.clone();
                quad.object = Term::NamedNode(empty_node);

                let key = self.document.dataset_mut().quads.insert(quad);
                let datatype_state = combo_box::State::new(self.abbreviated_datatypes.clone());
                let state = RowState {
                    read_only: false,
                    datatype_state,
                };
                task = Task::done(Message::AddRow(Some((key, state))));
            }
            Message::AddRow(Some((key, state))) => {
                self.document
                    .dataset_mut()
                    .associated_data
                    .insert(key, state);

                self.modified = true;
            }
            Message::DeleteRow(key) => {
                self.document.dataset_mut().remove(key);
                self.modified = true;
            }
            Message::OpenQueryWindow(action) => {
                let selected_entity_class = match action {
                    SearchResultClickAction::Predicate(_) => Some(vocab::rdf::PROPERTY),
                    SearchResultClickAction::Object(key) => {
                        self.document.dataset().quads.get(key).and_then(|quad| {
                            if quad.predicate == vocab::rdf::TYPE {
                                Some(vocab::rdfs::CLASS)
                            } else {
                                None
                            }
                        })
                    }
                    SearchResultClickAction::URLInput => None,
                };

                if let Some(search_state) = &mut self.search_state {
                    search_state.action = action;
                } else {
                    let (id, window_task) = window::open(Settings::default());
                    self.search_state = Some(SearchState {
                        window_id: id,
                        action,
                        entity_class_selection: None,
                        query: String::new(),
                        results: Vec::new(),
                    });
                    task = window_task.then(|_| operation::focus("query"));
                }

                if let Some(selected_entity_class) = selected_entity_class &&
                    let Some(class) = Class::try_from_named_node(selected_entity_class) {
                   task = task.chain(Task::done(Message::UpdateQueryClass(class)))
                }
            }
            Message::UpdateQueryClass(type_) => {
                if let Some(search_state) = &mut self.search_state {
                    search_state.entity_class_selection = Some(type_);
                    task = Task::done(Message::QueryUpdated(search_state.query.clone()));
                }
            }
            Message::QueryUpdated(new_query) => {
                if let Some(search_state) = &mut self.search_state {
                    let category_id = search_state.entity_class_selection
                        .as_ref()
                        .map(|selection| selection.to_owned() as u64);

                    let query = new_query.clone();
                    search_state.query = new_query;
                    let results = self
                        .index
                        .query(category_id, query.as_str(), Schema::all_fields(), 25)
                        .expect("Unable to complete search");
                    task = Task::done(Message::SetSearchResults(results));
                };
            }
            Message::SetSearchResults(results) => {
                if let Some(search_state) = &mut self.search_state {
                    search_state.results = results;
                }
            }
            Message::SearchResultClicked(node) => {
                if let Some(search_state) = &self.search_state {
                    task = task.chain(Task::done(Message::LookupResourceDescriptions(HashSet::from_iter([node.clone()]))));

                    match search_state.action {
                        SearchResultClickAction::URLInput => {
                            task = Task::done(Message::URLInputChanged(node.as_str().to_string()))
                                .chain(Task::done(Message::URLInputSubmitted));
                        }
                        SearchResultClickAction::Predicate(key) => {
                            if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                                quad.predicate = node;
                            }
                        }
                        SearchResultClickAction::Object(key) => {
                            if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                                quad.object = Term::NamedNode(node);
                            }
                        }
                    }
                    task = task.chain(window::close(search_state.window_id));
                    self.modified = true;
                }
            }
            Message::HoverRow(index) => {
                self.hovered_row = Some(index);
            }
            Message::UnhoverRow(index) if self.hovered_row == Some(index) => {
                self.hovered_row = None;
            }
            Message::DatatypeUpdated(key, Some(maybe_prefixed_iri)) => {
                let node = self
                    .curie_helper
                    .expand(None, &maybe_prefixed_iri)
                    .unwrap_or(maybe_prefixed_iri);

                if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                    let mut term = TermHelperMut::new(&mut quad.object);
                    term.set_datatype(Some(NamedNode::new_unchecked(node)));
                    self.modified = true;
                }
            }
            Message::DatatypeUpdated(key, None) => {
                if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                    let mut term = TermHelperMut::new(&mut quad.object);
                    term.set_datatype(None);
                    self.modified = true;
                }
            }
            Message::LanguageUpdated(key, Some(language)) => {
                if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                    let mut term = TermHelperMut::new(&mut quad.object);
                    term.set_language(language.as_str());
                    self.modified = true;
                }
            }
            Message::LanguageUpdated(key, None) => {
                if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                    let mut term = TermHelperMut::new(&mut quad.object);
                    term.set_language("en");
                    self.modified = true;
                }
            }
            Message::SubjectUpdated(key, value) => {
                if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                    quad.subject = NamedOrBlankNode::NamedNode(NamedNode::new_unchecked(value));
                    self.modified = true;
                }
            }
            Message::PredicateUpdated(key, value) => {
                if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                    quad.predicate = NamedNode::new_unchecked(value);
                    self.modified = true;
                }
            }
            Message::ObjectUpdated(key, value) => {
                if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                    let mut term = TermHelperMut::new(&mut quad.object);
                    term.set_value(value);
                    self.modified = true;
                }
            }
            Message::DirectionToggled(key, direction) => {
                if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                    let mut term = TermHelperMut::new(&mut quad.object);
                    term.set_direction(direction);
                    self.modified = true;
                }
            }
            Message::SaveGraph(overwrite) => {
                let client = self.http_client.clone();
                let read_only_entities = self.read_only_entities.clone();
                let options = SerializationOptions::from_format(RdfFormat::Turtle)
                    .with_filter(move |triple| {
                        if triple.predicate == vocab::rdf::TYPE &&
                            let TermRef::NamedNode(node) = triple.object {
                            !read_only_entities.contains(&ReadOnlyEntity::Class(node.into_owned()))
                        } else {
                            !read_only_entities.contains(&ReadOnlyEntity::Property(triple.predicate.into_owned()))
                        }
                    });
                let request = self
                    .document
                    .to_update(options)
                    .expect("Failed to generate PUT request");
                let url = self.document.origin().clone();
                task = Task::future(async move {
                    match request.send(client, overwrite).await {
                        Ok(RdfSourceUpdateResponse::Success) => Message::FetchDocument(url),
                        Ok(RdfSourceUpdateResponse::DocumentModified(_)) => {
                            Message::ShowOverwriteConfirmationModal
                        }
                        Err(err) => Message::ShowError(format!("Failed to save graph: {err}")),
                    }
                });
            }
            Message::ShowOverwriteConfirmationModal => {
                self.show_overwrite_confirmation = true;
            }
            Message::HideOverwriteConfirmationModal => {
                self.show_overwrite_confirmation = false;
            }
            Message::ConfirmOverwrite => {
                task = Task::done(Message::SaveGraph(true))
                    .chain(Task::done(Message::HideOverwriteConfirmationModal));
            }
            Message::ShowNewDocumentButtons => {
                self.show_new_document_buttons = true;
            }
            Message::HideNewDocumentButtons => {
                self.show_new_document_buttons = false;
            }
            Message::NewDocument(class, None) => {
                let client = self.http_client.clone();
                task = tasks::navigate_to_next_url(client, class);
            }
            Message::NewDocument(class, Some(url)) => {
                let mut document: RdfSource<KeyedDataset<RowState>> = RdfSource::new(url.clone());
                let mut nodes_to_look_up = HashSet::new();
                let document_node = NamedNode::new_unchecked(url.as_str());
                for triple in &class.template(document_node) {
                    let quad = document.quad_from_triple(triple.into_owned());
                    document.dataset_mut().quads.insert(quad);

                    if triple.predicate == vocab::rdf::TYPE &&
                        let TermRef::NamedNode(node) = triple.object {
                        nodes_to_look_up.insert(node.into_owned());
                    } else {
                        nodes_to_look_up.insert(triple.predicate.into_owned());
                    }
                }

                task = Task::done(Message::LookupResourceDescriptions(nodes_to_look_up))
                    .chain(Task::done(Message::HideNewDocumentButtons))
                    .chain(Task::done(Message::URLInputChanged(url.to_string())))
                    .chain(Task::done(Message::LoadDocument(document)));
            }
            Message::ResetState => {
                self.modified = false;
                self.show_new_document_buttons = false;
                self.show_overwrite_confirmation = false;
                self.resource_not_found = false;
            }
            Message::NavigateToPredicate(key) => {
                if let Some(quad) = self.document.dataset_mut().quads.get_mut(key) {
                    let url = Url::parse(quad.predicate.as_str()).expect("Invalid URL");
                    task = Task::done(Message::URLInputChanged(url.to_string()))
                        .chain(Task::done(Message::URLInputSubmitted));
                }
            }
            Message::NavigateToObject(key) => {
                if let Some(quad) = self.document.dataset_mut().quads.get_mut(key)
                    && let Term::NamedNode(node) = &quad.object {
                        let url = Url::parse(node.as_str()).expect("Invalid URL");
                        task = Task::done(Message::URLInputChanged(url.to_string()))
                            .chain(Task::done(Message::URLInputSubmitted));
                }
            }
            Message::NavigateBack => {
                let url = self.navigator.back().clone();
                task = Task::done(Message::URLInputChanged(url.to_string()))
                    .chain(Task::done(Message::NavigateTo(url)));
            }
            Message::NavigateForward => {
                let url = self.navigator.forward().clone();
                task = Task::done(Message::URLInputChanged(url.to_string()))
                    .chain(Task::done(Message::NavigateTo(url)));
            }
            Message::SetShowReadOnly(value) => {
                self.show_read_only = value;
            }
            Message::SetShowInferredTriples(value) => {
                self.show_inferred_triples = value;
            }
            Message::RunInference => {
                if let Some(ontology) = &mut self.ontology {
                    let graph = self.document
                        .dataset()
                        .quads
                        .iter()
                        .map(|(_, quad)| Triple::from(quad.clone()))
                        .collect();

                    task = tasks::run_inference(ontology.clone(), graph);
                }
            }
            Message::SetInferredTriples(graph) => {
                if let Some(ontology) = &mut self.ontology {
                    let predicates = graph.iter()
                        .map(|triple| triple.predicate.into_owned());

                    let objects = graph.iter()
                        .filter_map(|triple| match triple.object {
                            TermRef::NamedNode(node) => Some(node.into_owned()),
                            _ => None,
                        });

                    let mut nodes_to_look_up: HashSet<NamedNode> = HashSet::from_iter(predicates);
                    nodes_to_look_up.extend(objects);
                    task = tasks::lookup_resource_descriptions(ontology.clone(), nodes_to_look_up);
                }

                self.inferred_triples = graph;
            }
            Message::Event(Event::KeyPressed {
                key: keyboard::Key::Named(key::Named::Tab),
                modifiers,
                ..
            }) => {
                if modifiers.shift() {
                    task = operation::focus_previous();
                } else {
                    task = operation::focus_next();
                }
            }
            _ => {}
        }
        task
    }

    pub(crate) fn title(&self, _window: window::Id) -> String {
        "Graph of Liberty Publisher".to_string()
    }

    pub(crate) fn subscription(&self) -> Subscription<Message> {
        Subscription::batch([
            window::close_events().map(Message::WindowClosed),
            keyboard::listen().map(Message::Event),
        ])
    }

    fn view_row<'a>(
        &'a self,
        key: QuadKey,
        quad: &'a Quad,
        state: &'a RowState,
    ) -> Element<'a, Message> {
        const BUTTON_WIDTH: Length = Length::Fixed(35.0);
        let delete_button = button("\u{274c}")
            .style(|_, _| Style::default().with_background(Background::Color(color!(255, 0, 0))))
            .on_press(Message::DeleteRow(key));

        let button_area = if self.hovered_row == Some(key) && !state.read_only {
            container(delete_button).width(BUTTON_WIDTH)
        } else {
            container(space()).width(BUTTON_WIDTH)
        };

        let base = self.document.origin();

        let subject = match &quad.subject {
            NamedOrBlankNode::NamedNode(subject) => subject.as_str(),
            _ => "",
        };

        let subject_input_base = iri_input(&self.curie_helper, "Subject", Some(base), subject);
        let subject_input = if state.read_only {
            subject_input_base
        } else {
            subject_input_base.on_input(move |value| Message::SubjectUpdated(key, value))
        };

        let predicate_input_base = iri_input(
            &self.curie_helper,
            "Predicate",
            Some(base),
            quad.predicate.as_str(),
        );
        let predicate_input = if state.read_only {
            predicate_input_base
        } else {
            predicate_input_base
                .on_input(move |value| Message::PredicateUpdated(key, value))
                .on_control_click(Message::OpenQueryWindow(
                    SearchResultClickAction::Predicate(key),
                ))
                .on_shift_click(Message::NavigateToPredicate(key))
        };

        let predicate_label = self.resource_descriptions
            .get(&quad.predicate)
            .and_then(|description| description.label.clone())
            .map(|label| container(text(label)));

        let term = TermHelper::new(&quad.object);

        let value_label = term.value_as_named_node()
            .and_then(|node| self.resource_descriptions.get(&node.into_owned()))
            .and_then(|description| description.label.clone())
            .map(|label| container(text(label)));

        let value = term
            .value_as_named_node()
            .map(|node| node.as_str().to_string())
            .unwrap_or(term.value().to_string());

        let value_alignment = term
            .direction()
            .map(|direction| match direction {
                BaseDirection::Ltr => Horizontal::Left,
                BaseDirection::Rtl => Horizontal::Right,
            })
            .unwrap_or(Horizontal::Left);

        // If the datatype is something, then it's not a named node, and we should use a plain
        // text_input as opposed to an iri_input.
        let object_input: Element<Message> = if term.datatype().is_some() {
            let base = text_input("Object", value.clone());
            if state.read_only {
                base.into()
            } else {
                base.on_input(move |value| Message::ObjectUpdated(key, value))
                    .into()
            }
        } else {
            let base = iri_input(&self.curie_helper, "Object", Some(base), value.as_str())
                .on_shift_click(Message::NavigateToObject(key));
            if state.read_only {
                base.into()
            } else {
                base.align_x(value_alignment)
                    .on_input(move |value| Message::ObjectUpdated(key, value))
                    .on_control_click(Message::OpenQueryWindow(SearchResultClickAction::Object(
                        key,
                    )))
                    .into()
            }
        };

        let selected_datatype = term
            .datatype()
            .and_then(|node| self.curie_helper.abbreviate(None, node.as_str()));

        let datatype_selector: Element<Message> = if state.read_only {
            selected_datatype.map(text).into()
        } else {
            combo_box(
                &state.datatype_state,
                "Datatype",
                selected_datatype.as_ref(),
                move |selection| Message::DatatypeUpdated(key, Some(selection)),
            )
            .on_input(move |input| {
                let value = if input.is_empty() { None } else { Some(input) };
                Message::DatatypeUpdated(key, value)
            })
            .into()
        };

        let language = term.language().unwrap_or("en").to_owned();
        let language_input = match term.datatype() {
            Some(vocab::rdf::LANG_STRING) | Some(vocab::rdf::DIR_LANG_STRING) => Some(container(
                text_input("Language", language).on_input(move |input| {
                    let value = if input.is_empty() { None } else { Some(input) };
                    Message::LanguageUpdated(key, value)
                }),
            )),
            _ => None,
        };

        let direction_slider = term
            .direction()
            .map(|direction| match direction {
                BaseDirection::Ltr => toggler(false),
                BaseDirection::Rtl => toggler(true),
            })
            .map(|toggler| {
                container(row![
                    text("LTR"),
                    toggler.on_toggle(move |new_state| {
                        let direction = if new_state {
                            BaseDirection::Rtl
                        } else {
                            BaseDirection::Ltr
                        };
                        Message::DirectionToggled(key, direction)
                    }),
                    text("RTL"),
                ])
            });

        let row = row![
            button_area,
            subject_input,
            predicate_input,
            predicate_label,
            object_input,
            value_label,
            datatype_selector,
            language_input,
            direction_slider,
        ];

        mouse_area(row)
            .on_enter(Message::HoverRow(key))
            .on_exit(Message::UnhoverRow(key))
            .into()
    }

    fn view_search_window<'a>(&'a self, search_state: &'a SearchState) -> Element<'a, Message> {
        let search_input = text_input("Query", &search_state.query)
            .on_input(Message::QueryUpdated)
            .id("query");

        let type_selector = pick_list(
            search_state.entity_class_selection.as_ref(),
            Class::ALL,
            ToString::to_string,
        ).on_select(Message::UpdateQueryClass);

        let mut columns = vec![table::column(text("CURIE"), |document: &HashMap<gl_search::Field, gl_search::OwnedValue>| {
            let iri = document.get(&Schema::iri_field())
                .and_then(|value| value.as_str())
                .unwrap_or_default();

            let abbreviated_iri = document.get(&Schema::curie_field())
                .and_then(|value| value.as_str())
                .unwrap_or_default();

            button(text(abbreviated_iri).wrapping(Wrapping::Word))
                .on_press(Message::SearchResultClicked(NamedNode::new_unchecked(iri)))
                .style(button::text)
        })];

        let fields = search_state.entity_class_selection
            .as_ref()
            .map(|class| {
                class.fields(language::ENGLISH_TAG.clone())
            }).unwrap_or_default();

        for (field, label) in fields {
            columns.push(
                table::column(text(label), move |document: &HashMap<gl_search::Field, gl_search::OwnedValue>| {
                    let iri = document.get(&Schema::iri_field())
                        .and_then(|value| value.as_str())
                        .unwrap_or_default();

                    let value = document
                        .get(&field)
                        .and_then(|value| value.as_str())
                        .unwrap_or_default();

                    button(text(value).wrapping(Wrapping::Word))
                        .on_press(Message::SearchResultClicked(NamedNode::new_unchecked(iri)))
                        .style(button::text)
                })
                    .width(Length::Fixed(256.0)),
            );
        }

        let results_table = if columns.is_empty() {
            None
        } else {
            Some(scrollable(table(columns, &search_state.results)))
        };

        column![row![search_input, type_selector], results_table].into()
    }

    pub(crate) fn view(&self, window: window::Id) -> Element<'_, Message> {
        if let Some(search_state) = &self.search_state &&
            search_state.window_id == window {
            return self.view_search_window(search_state);
        }

        let back_button = button("\u{1f870}").on_press(Message::NavigateBack);
        let forward_button = button("\u{1f872}").on_press(Message::NavigateForward);
        let new_document_button = button("New Document").on_press(Message::ShowNewDocumentButtons);
        let add_row_button = button("Add Row").on_press(Message::AddRow(None));

        let address_input = iri_input(&self.curie_helper, "URL", None, &self.url_input)
            .on_input(Message::URLInputChanged)
            .on_submit(Message::URLInputSubmitted)
            .on_control_click(Message::OpenQueryWindow(SearchResultClickAction::URLInput))
            .style(crate::theme::styles::text_input::required(
                !self.url_input_valid,
            ));

        let mut rows: Vec<Element<Message>> = vec![];
        rows = self.document
            .dataset()
            .iter_both()
            .filter(|(_, _, state)| self.show_read_only || !state.read_only)
            .map(|(key, quad, state)| self.view_row(key, quad, state))
            .collect();

        let body: Element<Message> = if self.show_new_document_buttons {
            let buttons = Class::CREATABLE.iter()
                .map(|class| {
                    let url = if self.resource_not_found {
                        Url::parse(&self.url_input).ok()
                    } else { None };

                    button(text(class.to_string()))
                        .on_press(Message::NewDocument(class.clone(), url))
                        .into()
                });

            column![
                grid(buttons).height(Sizing::EvenlyDistribute(Length::Shrink))
            ].into()
        } else {
            column(rows).into()
        };

        let inference_table = if self.show_inferred_triples {
            let subject_column = table::column("Subject", |triple: TripleRef| {
                let curie = if let NamedOrBlankNodeRef::NamedNode(subject) = triple.subject {
                    Some(self.curie_helper
                        .abbreviate(Some(self.document.origin()), subject.as_str())
                        .unwrap_or_else(|| subject.as_str().to_string()))
                } else {
                    None
                };

                curie.map(text)
            });

            let predicate_column = table::column("Predicate", |triple: TripleRef| {
                let curie = self.curie_helper
                    .abbreviate(None, triple.predicate.as_str())
                    .unwrap_or_else(|| triple.predicate.as_str().to_string());

                let label = self.resource_descriptions
                    .get(&triple.predicate.into_owned())
                    .and_then(|description| description.label.clone());

                if let Some(label) = label {
                    text(format!("{curie} ({label})"))
                } else {
                    text(curie)
                }
            });

            let object_column = table::column("Object", |triple: TripleRef| {
                match triple.object {
                    TermRef::NamedNode(node) => {
                        let curie = self.curie_helper
                            .abbreviate(Some(self.document.origin()), node.as_str())
                            .unwrap_or_else(|| node.as_str().to_string());

                        let label = self.resource_descriptions
                            .get(&node.into_owned())
                            .and_then(|description| description.label.clone());

                        if let Some(label) = label {
                            text(format!("{curie} ({label})"))
                        } else {
                            text(curie)
                        }
                    }
                    _ => text(triple.object.to_string()),
                }
            });
            Some(table(
                [subject_column, predicate_column, object_column],
                self.inferred_triples.iter(),
            ))
        } else {
            None
        };

        let save_button_base = button(text("\u{1f4be}"));
        let save_button = if self.modified {
            save_button_base.on_press(Message::SaveGraph(false))
        } else {
            save_button_base
        };

        let inferred_triples_toggle =
            toggler(self.show_inferred_triples).on_toggle(Message::SetShowInferredTriples);

        let read_only_toggle = toggler(self.show_read_only).on_toggle(Message::SetShowReadOnly);

        let footer = row![
            space::horizontal(),
            text("Show Inferred Triples"),
            inferred_triples_toggle,
            space::horizontal(),
            text("Show Read Only Triples"),
            read_only_toggle
        ];

        let content = navigation_area(column![
            row![
                new_document_button,
                add_row_button,
                back_button,
                forward_button,
                address_input,
                save_button,
            ],
            footer,
            scrollable(body),
            scrollable(inference_table),
        ])
        .on_back_click(Message::NavigateBack)
        .on_forward_click(Message::NavigateForward);

        if self.show_overwrite_confirmation {
            let confirmation_modal = container(column![
                text("The resource has changed since it was fetched. Overwrite?"),
                row![
                    button(text("Yes"))
                        .style(button::danger)
                        .on_press(Message::ConfirmOverwrite),
                    space::horizontal(),
                    button(text("No")).on_press(Message::HideOverwriteConfirmationModal),
                ],
            ])
            .width(Length::Shrink);

            modal(content, confirmation_modal, Message::None)
        } else {
            content.into()
        }
    }
}

fn modal<'a, Message>(
    base: impl Into<Element<'a, Message>>,
    content: impl Into<Element<'a, Message>>,
    on_blur: Message,
) -> Element<'a, Message>
where
    Message: Clone + 'a,
{
    stack![
        base.into(),
        opaque(
            mouse_area(center(opaque(content)).style(|_theme| {
                container::Style {
                    background: Some(
                        Color {
                            a: 0.8,
                            ..Color::BLACK
                        }
                        .into(),
                    ),
                    ..container::Style::default()
                }
            }))
            .on_press(on_blur)
        )
    ]
    .into()
}