use crate::rdf::ontology::Ontology;
use crate::rdf::term_helper::{TermHelper, TermHelperMut};
use crate::rdf::vocab::{gl, rda};
use gl_search::{Schema, SearchDocument, SearchIndex, doc};
use http::StatusCode;
use iced::alignment::Horizontal;
use iced::widget::button::Style;
use iced::widget::grid::Sizing;
use iced::widget::{
    button, center, column, combo_box, container, grid, mouse_area, opaque, row, scrollable, space,
    stack, table, text, text_input, toggler,
};
use iced::window::Settings;
use iced::{Background, Color, Element, Length, Subscription, Task, color, window};
use ldp::middleware::BasicAuthMiddleware;
use ldp::model::{KeyedDataset, QuadKey};
use ldp::reqwest::{Client, Url};
use ldp::reqwest_middleware::{ClientBuilder, ClientWithMiddleware};
use ldp::traverse::Traverse;
use ldp::{RdfSource, RdfSourceUpdateResponse, ResourceRequestBuilder, SerializationOptions};
use oxigraph::io::RdfFormat;
use oxigraph::model::vocab::rdf;
use oxigraph::model::{BaseDirection, Dataset, NamedNode, Quad, Term, TermRef};
use tracing::{debug, error};

const ANNOTATED_IRI_TYPE: u64 = 0;

#[derive(Debug, Clone)]
pub(crate) enum Message {
    None,
    Traverse,
    IndexRdfSource(RdfSource<Dataset>),
    CommitIndex,
    WindowClosed(window::Id),
    URLInputChanged(String),
    URLInputSubmitted,
    FetchDocument(Url),
    LoadDocument(RdfSource<KeyedDataset<RowState>>),
    ShowNewDocumentButtons,
    HideNewDocumentButtons,
    ShowError(String),
    AddRow(Option<QuadKey>),
    DeleteRow(QuadKey),
    DeleteAllRows,
    OpenQueryWindow(SearchResultClickAction),
    HoverRow(QuadKey),
    UnhoverRow(QuadKey),
    QueryUpdated(String),
    SearchResultClicked(NamedNode),
    DatatypeUpdated(QuadKey, Option<String>),
    LanguageUpdated(QuadKey, Option<String>),
    ValueUpdated(QuadKey, String),
    DirectionToggled(QuadKey, BaseDirection),
    SaveGraph(bool),
    ShowOverwriteConfirmationModal,
    HideOverwriteConfirmationModal,
    ConfirmOverwrite,
    NewDocument(NamedNode),
    ResetState,
}

#[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,
    query: String,
    results: Vec<NamedNode>,
}

pub(crate) struct Publisher {
    http_client: ClientWithMiddleware,
    ontology: Ontology,
    abbreviated_datatypes: Vec<String>,
    window_id: window::Id,
    url_input: String,
    document: RdfSource<KeyedDataset<RowState>>,
    hovered_row: Option<QuadKey>,
    search_state: Option<SearchState>,
    index: SearchIndex,
    show_overwrite_confirmation: bool,
    modified: bool,
    show_new_document_buttons: bool,
}

impl Publisher {
    pub(crate) fn new() -> (Self, Task<Message>) {
        let ontology = Ontology::builder()
            .with_default_ontologies()
            .build()
            .expect("Failed to build ontology");

        let mut index = SearchIndex::builder()
            .with_path("/home/alex/Documents/Index")
            .build()
            .expect("Failed to build search index");

        index.remove_all_of_type(ANNOTATED_IRI_TYPE);
        ontology.for_each_annotated_iri(|iri, label, comment| {
            let mut document = doc!(
                Schema::type_field() => ANNOTATED_IRI_TYPE,
                Schema::iri_field() => iri,
            );

            if let Some(label) = label {
                document.add_text(Schema::field("label"), label.to_lowercase());
            }

            if let Some(comment) = comment {
                document.add_text(Schema::field("comment"), comment.to_lowercase());
            }

            index
                .add(document)
                .expect("Unable to add annotated IRI to search index");
        });
        index.commit().expect("Unable to commit ontology to index");

        let mut abbreviated_datatypes = ontology
            .datatypes()
            .map(|node| ontology.abbreviate(node))
            .collect::<Vec<_>>();
        abbreviated_datatypes.sort();

        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 url_input = "http://fedora.quill.lan/rest/".to_string();
        let document = RdfSource::new(Url::parse(&url_input).unwrap());

        (
            Self {
                http_client,
                ontology,
                abbreviated_datatypes,
                window_id: id,
                url_input,
                document,
                hovered_row: None,
                search_state: None,
                index,
                show_overwrite_confirmation: false,
                modified: false,
                show_new_document_buttons: false,
            },
            task.map(|_| Message::None),
        )
    }

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

        match message {
            Message::Traverse => {
                let client = self.http_client.clone();
                let root = Url::parse(&self.url_input).expect("Invalid URL");
                let stream = Traverse::new(client, root, None);
                task = Task::run(stream, |result| match result {
                    Ok(rdf_source) => Message::IndexRdfSource(rdf_source),
                    Err(err) => Message::ShowError(format!("Unable to fetch RDF Source: {err}")),
                })
                .chain(Task::done(Message::CommitIndex));
            }
            Message::IndexRdfSource(rdf_source) => {
                let catalog_id = rdf_source
                    .classes()
                    .filter_map(|class| self.ontology.catalog_id(&class.into_owned()))
                    .next();
                if let Some(catalog_id) = catalog_id {
                    let mut document = SearchDocument::new();
                    document.add_u64(Schema::type_field(), catalog_id);
                    document.add_text(Schema::iri_field(), rdf_source.origin());

                    for quad in rdf_source.dataset() {
                        if let Some(field_name) =
                            self.ontology.field_name(&quad.predicate.into_owned())
                            && let TermRef::Literal(literal) = quad.object
                        {
                            let field = Schema::schema()
                                .get_field(&field_name)
                                .expect("Field not found in schema");
                            document.add_text(field, literal.value().to_lowercase());
                        }
                    }

                    self.index
                        .add(document)
                        .expect("Unable to add document to search index");
                }
            }
            Message::CommitIndex => {
                if let Err(err) = self.index.commit() {
                    task = Task::done(Message::ShowError(format!("Unable to commit index: {err}")));
                }
            }
            Message::WindowClosed(id) => {
                if self.window_id == id {
                    task = iced::exit();
                } else {
                    self.search_state = None;
                }
            }
            Message::URLInputChanged(value) => {
                self.url_input = value;
            }
            Message::URLInputSubmitted => {
                let url = Url::parse(&self.url_input).expect("Invalid URL");
                task = Task::done(Message::DeleteAllRows)
                    .chain(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::ShowNewDocumentButtons
                            } else {
                                Message::ShowError(err.to_string())
                            }
                        }
                        Err(err) => Message::ShowError(format!("Request failed: {err}")),
                    }
                });
            }
            Message::LoadDocument(document) => {
                let messages = document
                    .dataset()
                    .quads
                    .keys()
                    .map(|key| Message::AddRow(Some(key)));
                task = Task::batch(messages.map(Task::done)).chain(Task::done(Message::ResetState));

                self.document = document;
            }
            Message::ShowError(error) => {
                error!(error);
            }
            Message::AddRow(None) => {
                let quad = self.document.new_quad();
                let key = self.document.dataset_mut().quads.insert(quad);
                task = Task::done(Message::AddRow(Some(key)));
            }
            Message::AddRow(Some(key)) => {
                let quad = self
                    .document
                    .dataset()
                    .quads
                    .get(key)
                    .expect("Failed to get quad from document");
                let read_only = self.ontology.is_read_only(quad.as_ref());
                let term = TermHelper::new(&quad.object);
                let datatype = term
                    .datatype()
                    .map(|datatype| self.ontology.abbreviate(datatype));
                let datatype_state = combo_box::State::with_selection(
                    self.abbreviated_datatypes.clone(),
                    datatype.as_ref(),
                );
                let state = RowState {
                    read_only,
                    datatype_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::DeleteAllRows => {
                self.document.dataset_mut().clear();
                self.modified = true;
            }
            Message::OpenQueryWindow(action) => {
                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,
                        query: String::new(),
                        results: Vec::new(),
                    });
                    task = window_task.map(|_| Message::None)
                }
            }
            Message::QueryUpdated(new_query) => {
                if let Some(search_state) = &mut self.search_state {
                    search_state.results = self
                        .index
                        .query(0, new_query.as_str(), Schema::all_fields())
                        .expect("Error encountered while querying index")
                        .iter()
                        .map(NamedNode::new_unchecked)
                        .collect();
                    search_state.query = new_query;
                };
            }
            Message::SearchResultClicked(node) => {
                if let Some(search_state) = &self.search_state {
                    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
                    .ontology
                    .expand(&maybe_prefixed_iri)
                    .unwrap_or(NamedNode::new_unchecked(&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(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::ValueUpdated(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 options = SerializationOptions::from_format(RdfFormat::Turtle)
                    .with_filter(self.ontology.exclude_read_only_predicate());
                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) => {
                let url = Url::parse(self.url_input.as_str()).expect("Invalid URL");
                let subject = NamedNode::new_unchecked(url.as_str());
                self.document = RdfSource::new(url);

                let quads = self
                    .ontology
                    .template_triples(class.as_ref(), subject.as_ref())
                    .map(|triples| {
                        triples
                            .map(|triple| self.document.quad_from_triple(triple))
                            .collect::<Vec<_>>()
                    });

                if let Some(quads) = quads {
                    let new_keys = self.document.dataset_mut().extend(quads.into_iter());
                    let messages = new_keys.map(|triple| Message::AddRow(Some(triple)));
                    task = Task::done(Message::HideNewDocumentButtons)
                        .chain(Task::batch(messages.map(Task::done)));
                }
            }
            Message::ResetState => {
                self.modified = false;
                self.show_new_document_buttons = false;
                self.show_overwrite_confirmation = false;
            }
            _ => {}
        }
        task
    }

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

    pub(crate) fn subscription(&self) -> Subscription<Message> {
        window::close_events().map(Message::WindowClosed)
    }

    fn view_row<'a>(
        &'a self,
        key: QuadKey,
        triple: &'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 property_label = self
            .ontology
            .info(triple.predicate.as_ref())
            .and_then(|info| info.label.clone())
            .unwrap_or(self.ontology.abbreviate(triple.predicate.as_ref()));

        let property: Element<Message> = if state.read_only {
            text(property_label).into()
        } else {
            button(text(property_label))
                .on_press(Message::OpenQueryWindow(
                    SearchResultClickAction::Predicate(key),
                ))
                .style(button::text)
                .into()
        };

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

        let value_label = term.value_as_named_node().and_then(|node| {
            self.ontology
                .info(node)
                .and_then(|info| info.label.clone())
                .map(|label| container(text(label)))
        });

        let value = term
            .value_as_named_node()
            .map(|node| self.ontology.abbreviate(node))
            .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);

        let value_input_base = text_input("Value", value.as_str()).align_x(value_alignment);

        let value_input = if !state.read_only {
            let is_named_node = term.is_named_node();
            value_input_base.on_input(move |input| {
                let expanded_input = if is_named_node {
                    self.ontology
                        .expand(input.as_str())
                        .map(|node| node.as_str().to_string())
                        .unwrap_or(input)
                } else {
                    input
                };

                Message::ValueUpdated(key, expanded_input)
            })
        } else {
            value_input_base
        };

        let search_launcher = if term.is_named_node() && !state.read_only {
            Some(container(
                button(text("\u{1f50e}"))
                    .on_press(Message::OpenQueryWindow(SearchResultClickAction::Object(
                        key,
                    )))
                    .style(button::text),
            ))
        } else {
            None
        };

        let selected_datatype = term.datatype().map(|node| self.ontology.abbreviate(node));
        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_input = match term.datatype() {
            Some(rdf::LANG_STRING) | Some(rdf::DIR_LANG_STRING) => Some(container(
                text_input("Language", term.language().unwrap_or("en")).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,
            property,
            value_label,
            value_input,
            search_launcher,
            datatype_selector,
            language_input,
            direction_slider,
        ];

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

    fn view_new_entity_buttons(
        &self,
        entities: impl Iterator<Item = NamedNode>,
    ) -> Element<'_, Message> {
        let buttons = entities.map(|entity| {
            let label = self
                .ontology
                .info(entity.as_ref())
                .and_then(|info| info.label.clone())
                .unwrap_or(entity.as_str().to_string());
            button(text(label))
                .on_press(Message::NewDocument(entity))
                .into()
        });

        grid(buttons)
            .height(Sizing::EvenlyDistribute(Length::Shrink))
            .into()
    }

    pub(crate) fn view(&self, window: window::Id) -> Element<'_, Message> {
        if let Some(search_state) = &self.search_state
            && search_state.window_id == window
        {
            let search_input =
                text_input("Query", &search_state.query).on_input(Message::QueryUpdated);

            let label_column = table::column("Label", |result: &NamedNode| {
                let header_text = self
                    .ontology
                    .info(result.as_ref())
                    .and_then(|info| info.label.clone())
                    .unwrap_or("".to_string());

                button(text(header_text))
                    .on_press(Message::SearchResultClicked(result.clone()))
                    .style(button::text)
            });

            let type_column = table::column("Type", |result: &NamedNode| {
                let header_text = self
                    .ontology
                    .info(result.as_ref())
                    .map(|info| info.type_.to_string())
                    .unwrap_or("Unknown".to_string());

                button(text(header_text))
                    .on_press(Message::SearchResultClicked(result.clone()))
                    .style(button::text)
            });

            /*let description_column = table::column("Description", |result: &NamedNode| {
                let header_text = self.ontology.info(result.as_ref())
                    .and_then(|info| info.comment.clone())
                    .unwrap_or("Unknown".to_string());

                button(text(header_text))
                    .on_press(Message::SearchResultClicked(result.clone()))
                    .style(button::text)
            });*/

            let iri_column = table::column("IRI", |result: &NamedNode| {
                button(text(result.as_str()))
                    .on_press(Message::SearchResultClicked(result.clone()))
                    .style(button::text)
            });

            let results_table = scrollable(table(
                [
                    label_column,
                    //description_column,
                    type_column,
                    iri_column,
                ],
                &search_state.results,
            ));

            return column![search_input, results_table].into();
        }

        let add_row_button = button("Add row").on_press(Message::AddRow(None));

        let index_button = button("Index").on_press(Message::Traverse);

        let search_launcher = button(text("\u{1f50e}"))
            .on_press(Message::OpenQueryWindow(SearchResultClickAction::URLInput))
            .style(button::text);

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

        let body: Element<Message> = if self.show_new_document_buttons {
            column![
                self.view_new_entity_buttons(self.ontology.subclass_of(gl::ENTITY)),
                self.view_new_entity_buttons(self.ontology.subclass_of(rda::ENTITY)),
            ]
            .into()
        } else {
            column(rows).into()
        };

        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 content = column![
            row![
                add_row_button,
                index_button,
                search_launcher,
                text_input("URL", &self.url_input)
                    .on_input(Message::URLInputChanged)
                    .on_submit(Message::URLInputSubmitted),
                save_button,
            ],
            scrollable(body),
            space::vertical(),
        ];

        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()
}