use std::collections::HashMap;

use charabia::Language;
use serde::{Deserialize, Serialize};
use utoipa::ToSchema;

use crate::attribute_patterns::PatternMatch;
use crate::fields_ids_map::FieldsIdsMap;
use crate::{AttributePatterns, FieldId};

/// A rule that defines which locales are supported for a given attribute.
///
/// The rule is a list of attribute patterns and a list of locales.
/// The attribute patterns are matched against the attribute name.
/// The pattern `*` matches any attribute name.
/// The pattern `attribute_name*` matches any attribute name that starts with `attribute_name`.
/// The pattern `*attribute_name` matches any attribute name that ends with `attribute_name`.
/// The pattern `*attribute_name*` matches any attribute name that contains `attribute_name`.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, ToSchema)]
pub struct LocalizedAttributesRule {
    pub attribute_patterns: AttributePatterns,
    #[schema(value_type = Vec<String>)]
    pub locales: Vec<Language>,
}

impl LocalizedAttributesRule {
    pub fn new(attribute_patterns: Vec<String>, locales: Vec<Language>) -> Self {
        Self { attribute_patterns: AttributePatterns::from(attribute_patterns), locales }
    }

    pub fn match_str(&self, str: &str) -> PatternMatch {
        self.attribute_patterns.match_str(str)
    }

    pub fn locales(&self) -> &[Language] {
        &self.locales
    }
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct LocalizedFieldIds {
    field_id_to_locales: HashMap<FieldId, Vec<Language>>,
}

impl LocalizedFieldIds {
    pub fn new<I: Iterator<Item = FieldId>>(
        rules: &Option<Vec<LocalizedAttributesRule>>,
        fields_ids_map: &FieldsIdsMap,
        fields_ids: I,
    ) -> Self {
        let mut field_id_to_locales = HashMap::new();

        if let Some(rules) = rules {
            let fields = fields_ids.filter_map(|field_id| {
                fields_ids_map.name(field_id).map(|field_name: &str| (field_id, field_name))
            });

            for (field_id, field_name) in fields {
                let mut locales = Vec::new();
                for rule in rules {
                    if rule.match_str(field_name) == PatternMatch::Match {
                        locales.extend(rule.locales.iter());
                        // Take the first rule that matches
                        break;
                    }
                }

                if !locales.is_empty() {
                    locales.sort();
                    locales.dedup();
                    field_id_to_locales.insert(field_id, locales);
                }
            }
        }

        Self { field_id_to_locales }
    }

    pub fn all_locales(&self) -> Vec<Language> {
        let mut locales = Vec::new();
        for field_locales in self.field_id_to_locales.values() {
            if !field_locales.is_empty() {
                locales.extend(field_locales);
            } else {
                // If a field has no locales, we consider it as not localized
                return Vec::new();
            }
        }
        locales.sort();
        locales.dedup();
        locales
    }
}