use crate::error;
use crate::rdf::conversion;
use gl_graph::language::LanguageCondition;
use gl_graph::vocab::gl;
use iced::futures::TryFutureExt;
use oxigraph::model::vocab::{rdf, rdfs, xsd};
use oxigraph::model::{
    Dataset, Graph, GraphNameRef, LiteralRef, NamedNode, NamedNodeRef, NamedOrBlankNode,
    NamedOrBlankNodeRef, Term, TermRef, Triple, TripleRef,
};
use oxigraph::sparql::{QueryResults, SparqlEvaluator};
use oxigraph::store::Store;
use std::collections::{BTreeMap, BTreeSet, HashMap};
use std::fmt::Display;
use std::path::{Path, PathBuf};
use std::sync::LazyLock;
use tracing::{debug_span, field};

const ONTOLOGY_PREFIX: &str = "https://graphofliberty.org/2026/04/ont/";
const ONTOLOGY_GRAPH_NAME: GraphNameRef = GraphNameRef::NamedNode(NamedNodeRef::new_unchecked(
    "https://graphofliberty.org/2026/04/ont",
));

static PREFIXES: LazyLock<BTreeMap<String, String>> = LazyLock::new(|| {
    BTreeMap::from_iter(
        [
            ("rdf", "http://www.w3.org/1999/02/22-rdf-syntax-ns#"),
            ("rdfs", "http://www.w3.org/2000/01/rdf-schema#"),
            ("owl", "http://www.w3.org/2002/07/owl#"),
            ("xsd", "http://www.w3.org/2001/XMLSchema#"),
            ("ldp", "http://www.w3.org/ns/ldp#"),
            ("dc", "http://purl.org/dc/elements/1.1/"),
            ("posix", "http://www.w3.org/ns/posix/stat#"),
            (
                "ebucore",
                "http://www.ebu.ch/metadata/ontologies/ebucore/ebucore#",
            ),
            ("prov", "http://www.w3.org/ns/prov#"),
            ("locid", "http://id.loc.gov/vocabulary/identifiers/"),
            ("loclang", "http://id.loc.gov/vocabulary/languages/"),
            ("premis", "http://www.loc.gov/premis/rdf/v1#"),
            ("premis3", "http://www.loc.gov/premis/rdf/v3/"),
            ("dcterms", "http://purl.org/dc/terms/"),
            ("fedora", "http://fedora.info/definitions/v4/repository#"),
            ("rdaa", "http://rdaregistry.info/Elements/a/"),
            ("rdac", "http://rdaregistry.info/Elements/c/"),
            ("rdae", "http://rdaregistry.info/Elements/e/"),
            ("rdai", "http://rdaregistry.info/Elements/i/"),
            ("rdam", "http://rdaregistry.info/Elements/m/"),
            ("rdan", "http://rdaregistry.info/Elements/n/"),
            ("rdap", "http://rdaregistry.info/Elements/p/"),
            ("rdaf", "http://rdaregistry.info/Elements/rof/"),
            ("rdat", "http://rdaregistry.info/Elements/t/"),
            ("rdau", "http://rdaregistry.info/Elements/u/"),
            ("rdaw", "http://rdaregistry.info/Elements/w/"),
            ("rdax", "http://rdaregistry.info/Elements/x/"),
            ("rdaco", "http://rdaregistry.info/termList/RDAContentType/"),
            ("rdact", "http://rdaregistry.info/termList/RDACarrierType/"),
            ("rdamt", "http://rdaregistry.info/termList/RDAMediaType/"),
            ("rdaft", "http://rdaregistry.info/termList/fileType/"),
            ("schema", "https://schema.org/"),
            ("gl", "http://fedora.quill.lan/rest/"),
            ("glo", ONTOLOGY_PREFIX),
        ]
        .map(|(k, v)| (k.to_string(), v.to_string())),
    )
});

pub struct OntologyBuilder {
    path: Option<PathBuf>,
}

impl OntologyBuilder {
    pub fn with_path(mut self, path: impl AsRef<Path>) -> Self {
        let path = path.as_ref().to_owned();
        self.path = Some(path);
        self
    }

    pub fn build(self) -> error::Result<Ontology> {
        let store = if let Some(path) = self.path {
            Store::open(path)
        } else {
            Store::new()
        }?;

        let prefixes = PREFIXES
            .iter()
            .map(|(k, v)| (k.to_string(), v.to_string()))
            .collect::<HashMap<String, String>>();

        /*let mut indexed_by = HashMap::new();
        for quad in store
            .quads_for_pattern(None, Some(gl::INDEXED_BY_FIELD), None, None)
            .filter_map(Result::ok)
        {
            if let NamedOrBlankNode::NamedNode(subject) = quad.subject
                && let Term::NamedNode(field) = quad.object
            {
                indexed_by.insert(subject, field);
            }
        }*/

        Ok(Ontology { store, prefixes })
    }
}

#[derive(Clone, Debug)]
pub struct IndexEntry {
    pub category_id: u64,
    pub fields: HashMap<String, String>,
}

#[derive(Clone, Debug, Eq)]
pub struct LabeledIri {
    pub iri: NamedNode,
    pub label: String,
}

impl PartialEq for LabeledIri {
    fn eq(&self, other: &Self) -> bool {
        self.iri == other.iri
    }
}

impl PartialOrd for LabeledIri {
    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
        self.label.partial_cmp(&other.label)
    }
}

impl Ord for LabeledIri {
    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
        self.label.cmp(&other.label)
    }
}

impl Display for LabeledIri {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{}", self.label)
    }
}

#[derive(Clone, Debug)]
pub struct IndexField {
    pub name: String,
    pub label: String,
}

pub struct Ontology {
    store: Store,
    prefixes: HashMap<String, String>,
}

impl Ontology {
    pub fn builder() -> OntologyBuilder {
        OntologyBuilder { path: None }
    }

    pub fn prefixes() -> &'static BTreeMap<String, String> {
        &*PREFIXES
    }

    pub fn to_dataset(&self) -> Dataset {
        self.store
            .quads_for_pattern(None, None, None, Some(ONTOLOGY_GRAPH_NAME))
            .filter_map(Result::ok)
            .collect::<Dataset>()
    }

    pub fn store(&self) -> Store {
        self.store.clone()
    }

    pub fn query_for_indexable_triples(
        &self,
        language: &LanguageCondition,
        source: Option<Dataset>,
    ) -> impl Future<Output = error::Result<HashMap<NamedNode, IndexEntry>>> + 'static {
        let language_filter = language.to_filter_expression("fieldValue");
        let query = format!(
            r#"SELECT ?individual ?categoryId ?fieldName ?fieldValue
WHERE {{
    ?class a gl:SearchableClass ;
    gl:categoryId ?categoryId ;
    gl:associatedProperty ?property .

    ?property gl:indexedByField/gl:fieldName ?fieldName .

    ?individual a ?class ;
    ?property ?fieldValue .

    {language_filter}
}}"#
        );
        let mut sparql = SparqlEvaluator::new()
            .with_prefix("gl", ONTOLOGY_PREFIX)
            .unwrap()
            .parse_query(&query)
            .expect("Unable to parse query");
        sparql.dataset_mut().set_default_graph_as_union();

        let store = self.store.clone();
        tokio::task::spawn_blocking(move || {
            let span = debug_span!("Indexable Triples Query", solutions = field::Empty).entered();
            let query_results = if let Some(source) = &source {
                sparql.on_queryable_dataset(source).execute()
            } else {
                sparql.on_store(&store).execute()
            }
            .expect("Unable to execute indexing query");

            let mut results = HashMap::new();
            if let QueryResults::Solutions(solutions) = query_results {
                let mut counter = 0usize;
                for solution in solutions.filter_map(Result::ok) {
                    let individual = solution
                        .get("individual")
                        .and_then(conversion::term_to_named_node);
                    let catalog_id = solution.get("categoryId").and_then(conversion::term_to_u64);
                    let field_name = solution.get("fieldName").and_then(conversion::term_as_str);
                    let field_value = solution.get("fieldValue").and_then(conversion::term_as_str);
                    if let (
                        Some(individual),
                        Some(catalog_id),
                        Some(field_name),
                        Some(field_value),
                    ) = (individual, catalog_id, field_name, field_value)
                    {
                        results
                            .entry(individual.to_owned())
                            .and_modify(|entry: &mut IndexEntry| {
                                entry
                                    .fields
                                    .insert(field_name.to_owned(), field_value.to_owned());
                            })
                            .or_insert(IndexEntry {
                                category_id: catalog_id,
                                fields: HashMap::from_iter([(
                                    field_name.to_owned(),
                                    field_value.to_owned(),
                                )]),
                            });
                    }
                    counter += 1;
                }
                span.record("solutions", counter);
            } else {
                unreachable!()
            }
            results
        })
        .map_err(error::Error::from)
    }

    pub fn category_id(&self, class: &NamedNode) -> Option<u64> {
        None
        /*self.store
            .quads_for_pattern(Some(class.into()), Some(gl::CATEGORY_ID), None, None)
            .filter_map(Result::ok)
            .map(conversion::quad_into_term)
            .filter_map(conversion::term_into_u64)
            .next()*/
    }

    pub fn fields_for_class(
        &self,
        class: &NamedNode,
        language: &LanguageCondition,
    ) -> error::Result<Vec<IndexField>> {
        let language_filter = language.to_filter_expression("label");
        let query = format!(
            r#"SELECT DISTINCT ?name ?label {{
    {class} gl:associatedProperty/gl:indexedByField ?field .

    ?field gl:fieldName ?name ;
    gl:fieldLabel ?label .

    {language_filter}
}}"#
        );
        let mut sparql = SparqlEvaluator::new()
            .with_prefix("rdfs", "http://www.w3.org/2000/01/rdf-schema#")?
            .with_prefix("gl", ONTOLOGY_PREFIX)?
            .parse_query(&query)?;
        sparql.dataset_mut().set_default_graph_as_union();

        let mut results = Vec::new();
        if let QueryResults::Solutions(solutions) = sparql.on_store(&self.store).execute()? {
            for solution in solutions.filter_map(Result::ok) {
                let name = solution.get("name").and_then(conversion::term_as_str);
                let label = solution.get("label").and_then(conversion::term_as_str);

                if let Some(name) = name
                    && let Some(label) = label
                {
                    results.push(IndexField {
                        name: name.to_string(),
                        label: label.to_string(),
                    });
                }
            }
        }
        Ok(results)
    }

    pub fn info(&self, iri: &NamedNode, language: &LanguageCondition) -> LabeledIri {
        let label = self
            .store
            .quads_for_pattern(Some(iri.as_ref().into()), Some(rdfs::LABEL), None, None)
            .filter_map(Result::ok)
            .map(conversion::quad_into_term)
            .filter(|term| language.primary_matches_term(term))
            .filter_map(conversion::term_into_string)
            .next()
            .unwrap_or_default();

        LabeledIri {
            iri: iri.clone(),
            label,
        }
    }

    pub fn subclasses_of(&self, class: &NamedNode) -> BTreeSet<NamedNode> {
        self.store
            .quads_for_pattern(None, Some(rdfs::SUB_CLASS_OF), Some(class.into()), None)
            .filter_map(Result::ok)
            .filter_map(|quad| {
                if let NamedOrBlankNode::NamedNode(subject) = quad.subject {
                    Some(subject)
                } else {
                    None
                }
            })
            .collect()
    }

    pub fn datatypes(&self) -> BTreeSet<NamedNode> {
        self.store
            .quads_for_pattern(
                None,
                Some(rdf::TYPE),
                Some(TermRef::NamedNode(rdfs::DATATYPE)),
                None,
            )
            .filter_map(Result::ok)
            .filter_map(|quad| match quad.subject {
                NamedOrBlankNode::NamedNode(subject) => Some(subject),
                _ => None,
            })
            .collect()
    }

    pub fn is_read_only<'a>(&self, triple: impl Into<TripleRef<'a>>) -> bool {
        let triple = triple.into();
        let true_term = TermRef::Literal(LiteralRef::new_typed_literal("true", xsd::BOOLEAN));

        let subject = match (triple.predicate, triple.object) {
            (rdf::TYPE, TermRef::NamedNode(class)) => class,
            (predicate, _) => predicate,
        };

        self.store
            .quads_for_pattern(
                Some(NamedOrBlankNodeRef::NamedNode(subject)),
                Some(gl::READ_ONLY),
                Some(true_term),
                None,
            )
            .filter_map(Result::ok)
            .count()
            >= 1
    }

    pub fn exclude_read_only(&self) -> impl Fn(TripleRef<'_>) -> bool + 'static {
        let true_term = TermRef::Literal(LiteralRef::new_typed_literal("true", xsd::BOOLEAN));
        let read_only_graph = self
            .store
            .quads_for_pattern(None, Some(gl::READ_ONLY), Some(true_term), None)
            .filter_map(Result::ok)
            .map(Triple::from)
            .collect::<Graph>();
        move |triple| {
            if triple.predicate == rdf::TYPE
                && let TermRef::NamedNode(class) = triple.object
            {
                read_only_graph.triples_for_subject(class).count() == 0
            } else {
                read_only_graph
                    .triples_for_subject(triple.predicate)
                    .count()
                    == 0
            }
        }
    }
}