use crate::database::{lock_conn, Database};
use crate::error::AppError;
use crate::provider::{Provider, ProviderMeta};
use indexmap::IndexMap;
use rusqlite::params;
use std::collections::HashMap;

type OmoProviderRow = (
    String,
    String,
    String,
    Option<String>,
    Option<i64>,
    Option<usize>,
    Option<String>,
    String,
);

impl Database {
    pub fn get_all_providers(
        &self,
        app_type: &str,
    ) -> Result<IndexMap<String, Provider>, AppError> {
        let conn = lock_conn!(self.conn);
        let mut stmt = conn.prepare(
            "SELECT id, name, settings_config, website_url, category, created_at, sort_index, notes, icon, icon_color, meta, in_failover_queue
             FROM providers WHERE app_type = ?1
             ORDER BY COALESCE(sort_index, 999999), created_at ASC, id ASC"
        ).map_err(|e| AppError::Database(e.to_string()))?;

        let provider_iter = stmt
            .query_map(params![app_type], |row| {
                let id: String = row.get(0)?;
                let name: String = row.get(1)?;
                let settings_config_str: String = row.get(2)?;
                let website_url: Option<String> = row.get(3)?;
                let category: Option<String> = row.get(4)?;
                let created_at: Option<i64> = row.get(5)?;
                let sort_index: Option<usize> = row.get(6)?;
                let notes: Option<String> = row.get(7)?;
                let icon: Option<String> = row.get(8)?;
                let icon_color: Option<String> = row.get(9)?;
                let meta_str: String = row.get(10)?;
                let in_failover_queue: bool = row.get(11)?;

                let settings_config =
                    serde_json::from_str(&settings_config_str).unwrap_or(serde_json::Value::Null);
                let meta: ProviderMeta = serde_json::from_str(&meta_str).unwrap_or_default();

                Ok((
                    id,
                    Provider {
                        id: "".to_string(), // Placeholder, set below
                        name,
                        settings_config,
                        website_url,
                        category,
                        created_at,
                        sort_index,
                        notes,
                        meta: Some(meta),
                        icon,
                        icon_color,
                        in_failover_queue,
                    },
                ))
            })
            .map_err(|e| AppError::Database(e.to_string()))?;

        let mut providers = IndexMap::new();
        for provider_res in provider_iter {
            let (id, mut provider) = provider_res.map_err(|e| AppError::Database(e.to_string()))?;
            provider.id = id.clone();

            let mut stmt_endpoints = conn.prepare(
                "SELECT url, added_at FROM provider_endpoints WHERE provider_id = ?1 AND app_type = ?2 ORDER BY added_at ASC, url ASC"
            ).map_err(|e| AppError::Database(e.to_string()))?;

            let endpoints_iter = stmt_endpoints
                .query_map(params![id, app_type], |row| {
                    let url: String = row.get(0)?;
                    let added_at: Option<i64> = row.get(1)?;
                    Ok((
                        url,
                        crate::settings::CustomEndpoint {
                            url: "".to_string(),
                            added_at: added_at.unwrap_or(0),
                            last_used: None,
                        },
                    ))
                })
                .map_err(|e| AppError::Database(e.to_string()))?;

            let mut custom_endpoints = HashMap::new();
            for ep_res in endpoints_iter {
                let (url, mut ep) = ep_res.map_err(|e| AppError::Database(e.to_string()))?;
                ep.url = url.clone();
                custom_endpoints.insert(url, ep);
            }

            if let Some(meta) = &mut provider.meta {
                meta.custom_endpoints = custom_endpoints;
            }

            providers.insert(id, provider);
        }

        Ok(providers)
    }

    pub fn get_current_provider(&self, app_type: &str) -> Result<Option<String>, AppError> {
        let conn = lock_conn!(self.conn);
        let mut stmt = conn
            .prepare("SELECT id FROM providers WHERE app_type = ?1 AND is_current = 1 LIMIT 1")
            .map_err(|e| AppError::Database(e.to_string()))?;

        let mut rows = stmt
            .query(params![app_type])
            .map_err(|e| AppError::Database(e.to_string()))?;

        if let Some(row) = rows.next().map_err(|e| AppError::Database(e.to_string()))? {
            Ok(Some(
                row.get(0).map_err(|e| AppError::Database(e.to_string()))?,
            ))
        } else {
            Ok(None)
        }
    }

    pub fn get_provider_by_id(
        &self,
        id: &str,
        app_type: &str,
    ) -> Result<Option<Provider>, AppError> {
        let conn = lock_conn!(self.conn);
        let result = conn.query_row(
            "SELECT name, settings_config, website_url, category, created_at, sort_index, notes, icon, icon_color, meta, in_failover_queue
             FROM providers WHERE id = ?1 AND app_type = ?2",
            params![id, app_type],
            |row| {
                let name: String = row.get(0)?;
                let settings_config_str: String = row.get(1)?;
                let website_url: Option<String> = row.get(2)?;
                let category: Option<String> = row.get(3)?;
                let created_at: Option<i64> = row.get(4)?;
                let sort_index: Option<usize> = row.get(5)?;
                let notes: Option<String> = row.get(6)?;
                let icon: Option<String> = row.get(7)?;
                let icon_color: Option<String> = row.get(8)?;
                let meta_str: String = row.get(9)?;
                let in_failover_queue: bool = row.get(10)?;

                let settings_config = serde_json::from_str(&settings_config_str).unwrap_or(serde_json::Value::Null);
                let meta: ProviderMeta = serde_json::from_str(&meta_str).unwrap_or_default();

                Ok(Provider {
                    id: id.to_string(),
                    name,
                    settings_config,
                    website_url,
                    category,
                    created_at,
                    sort_index,
                    notes,
                    meta: Some(meta),
                    icon,
                    icon_color,
                    in_failover_queue,
                })
            },
        );

        match result {
            Ok(provider) => Ok(Some(provider)),
            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(None),
            Err(e) => Err(AppError::Database(e.to_string())),
        }
    }

    pub fn save_provider(&self, app_type: &str, provider: &Provider) -> Result<(), AppError> {
        let mut conn = lock_conn!(self.conn);
        let tx = conn
            .transaction()
            .map_err(|e| AppError::Database(e.to_string()))?;

        let mut meta_clone = provider.meta.clone().unwrap_or_default();
        let endpoints = std::mem::take(&mut meta_clone.custom_endpoints);

        let existing: Option<(bool, bool)> = tx
            .query_row(
                "SELECT is_current, in_failover_queue FROM providers WHERE id = ?1 AND app_type = ?2",
                params![provider.id, app_type],
                |row| Ok((row.get(0)?, row.get(1)?)),
            )
            .ok();

        let is_update = existing.is_some();
        let (is_current, in_failover_queue) =
            existing.unwrap_or((false, provider.in_failover_queue));

        if is_update {
            tx.execute(
                "UPDATE providers SET
                    name = ?1,
                    settings_config = ?2,
                    website_url = ?3,
                    category = ?4,
                    created_at = ?5,
                    sort_index = ?6,
                    notes = ?7,
                    icon = ?8,
                    icon_color = ?9,
                    meta = ?10,
                    is_current = ?11,
                    in_failover_queue = ?12
                WHERE id = ?13 AND app_type = ?14",
                params![
                    provider.name,
                    serde_json::to_string(&provider.settings_config).map_err(|e| {
                        AppError::Database(format!("Failed to serialize settings_config: {e}"))
                    })?,
                    provider.website_url,
                    provider.category,
                    provider.created_at,
                    provider.sort_index,
                    provider.notes,
                    provider.icon,
                    provider.icon_color,
                    serde_json::to_string(&meta_clone).map_err(|e| AppError::Database(format!(
                        "Failed to serialize meta: {e}"
                    )))?,
                    is_current,
                    in_failover_queue,
                    provider.id,
                    app_type,
                ],
            )
            .map_err(|e| AppError::Database(e.to_string()))?;
        } else {
            tx.execute(
                "INSERT INTO providers (
                    id, app_type, name, settings_config, website_url, category,
                    created_at, sort_index, notes, icon, icon_color, meta, is_current, in_failover_queue
                ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12, ?13, ?14)",
                params![
                    provider.id,
                    app_type,
                    provider.name,
                    serde_json::to_string(&provider.settings_config)
                        .map_err(|e| AppError::Database(format!("Failed to serialize settings_config: {e}")))?,
                    provider.website_url,
                    provider.category,
                    provider.created_at,
                    provider.sort_index,
                    provider.notes,
                    provider.icon,
                    provider.icon_color,
                    serde_json::to_string(&meta_clone)
                        .map_err(|e| AppError::Database(format!("Failed to serialize meta: {e}")))?,
                    is_current,
                    in_failover_queue,
                ],
            )
            .map_err(|e| AppError::Database(e.to_string()))?;

            for (url, endpoint) in endpoints {
                tx.execute(
                    "INSERT INTO provider_endpoints (provider_id, app_type, url, added_at)
                     VALUES (?1, ?2, ?3, ?4)",
                    params![provider.id, app_type, url, endpoint.added_at],
                )
                .map_err(|e| AppError::Database(e.to_string()))?;
            }
        }

        tx.commit().map_err(|e| AppError::Database(e.to_string()))?;
        Ok(())
    }

    pub fn delete_provider(&self, app_type: &str, id: &str) -> Result<(), AppError> {
        let conn = lock_conn!(self.conn);
        conn.execute(
            "DELETE FROM providers WHERE id = ?1 AND app_type = ?2",
            params![id, app_type],
        )
        .map_err(|e| AppError::Database(e.to_string()))?;
        Ok(())
    }

    pub fn set_current_provider(&self, app_type: &str, id: &str) -> Result<(), AppError> {
        let mut conn = lock_conn!(self.conn);
        let tx = conn
            .transaction()
            .map_err(|e| AppError::Database(e.to_string()))?;

        tx.execute(
            "UPDATE providers SET is_current = 0 WHERE app_type = ?1",
            params![app_type],
        )
        .map_err(|e| AppError::Database(e.to_string()))?;

        tx.execute(
            "UPDATE providers SET is_current = 1 WHERE id = ?1 AND app_type = ?2",
            params![id, app_type],
        )
        .map_err(|e| AppError::Database(e.to_string()))?;

        tx.commit().map_err(|e| AppError::Database(e.to_string()))?;
        Ok(())
    }

    pub fn update_provider_settings_config(
        &self,
        app_type: &str,
        provider_id: &str,
        settings_config: &serde_json::Value,
    ) -> Result<(), AppError> {
        let conn = lock_conn!(self.conn);
        conn.execute(
            "UPDATE providers SET settings_config = ?1 WHERE id = ?2 AND app_type = ?3",
            params![
                serde_json::to_string(settings_config).map_err(|e| AppError::Database(format!(
                    "Failed to serialize settings_config: {e}"
                )))?,
                provider_id,
                app_type
            ],
        )
        .map_err(|e| AppError::Database(e.to_string()))?;
        Ok(())
    }

    pub fn add_custom_endpoint(
        &self,
        app_type: &str,
        provider_id: &str,
        url: &str,
    ) -> Result<(), AppError> {
        let conn = lock_conn!(self.conn);
        let added_at = chrono::Utc::now().timestamp_millis();
        conn.execute(
            "INSERT INTO provider_endpoints (provider_id, app_type, url, added_at) VALUES (?1, ?2, ?3, ?4)",
            params![provider_id, app_type, url, added_at],
        ).map_err(|e| AppError::Database(e.to_string()))?;
        Ok(())
    }

    pub fn remove_custom_endpoint(
        &self,
        app_type: &str,
        provider_id: &str,
        url: &str,
    ) -> Result<(), AppError> {
        let conn = lock_conn!(self.conn);
        conn.execute(
            "DELETE FROM provider_endpoints WHERE provider_id = ?1 AND app_type = ?2 AND url = ?3",
            params![provider_id, app_type, url],
        )
        .map_err(|e| AppError::Database(e.to_string()))?;
        Ok(())
    }

    pub fn set_omo_provider_current(
        &self,
        app_type: &str,
        provider_id: &str,
        category: &str,
    ) -> Result<(), AppError> {
        let mut conn = lock_conn!(self.conn);
        let tx = conn
            .transaction()
            .map_err(|e| AppError::Database(e.to_string()))?;
        tx.execute(
            "UPDATE providers SET is_current = 0 WHERE app_type = ?1 AND category = ?2",
            params![app_type, category],
        )
        .map_err(|e| AppError::Database(e.to_string()))?;
        let updated = tx
            .execute(
                "UPDATE providers SET is_current = 1 WHERE id = ?1 AND app_type = ?2 AND category = ?3",
                params![provider_id, app_type, category],
            )
            .map_err(|e| AppError::Database(e.to_string()))?;
        if updated != 1 {
            return Err(AppError::Database(format!(
                "Failed to set {category} provider current: provider '{provider_id}' not found in app '{app_type}'"
            )));
        }
        tx.commit().map_err(|e| AppError::Database(e.to_string()))?;
        Ok(())
    }

    pub fn is_omo_provider_current(
        &self,
        app_type: &str,
        provider_id: &str,
        category: &str,
    ) -> Result<bool, AppError> {
        let conn = lock_conn!(self.conn);
        match conn.query_row(
            "SELECT is_current FROM providers
             WHERE id = ?1 AND app_type = ?2 AND category = ?3",
            params![provider_id, app_type, category],
            |row| row.get(0),
        ) {
            Ok(is_current) => Ok(is_current),
            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(false),
            Err(e) => Err(AppError::Database(e.to_string())),
        }
    }

    pub fn clear_omo_provider_current(
        &self,
        app_type: &str,
        provider_id: &str,
        category: &str,
    ) -> Result<(), AppError> {
        let conn = lock_conn!(self.conn);
        conn.execute(
            "UPDATE providers SET is_current = 0
             WHERE id = ?1 AND app_type = ?2 AND category = ?3",
            params![provider_id, app_type, category],
        )
        .map_err(|e| AppError::Database(e.to_string()))?;
        Ok(())
    }

    pub fn get_current_omo_provider(
        &self,
        app_type: &str,
        category: &str,
    ) -> Result<Option<Provider>, AppError> {
        let conn = lock_conn!(self.conn);
        let row_data: Result<OmoProviderRow, rusqlite::Error> = conn.query_row(
            "SELECT id, name, settings_config, category, created_at, sort_index, notes, meta
             FROM providers
             WHERE app_type = ?1 AND category = ?2 AND is_current = 1
             LIMIT 1",
            params![app_type, category],
            |row| {
                Ok((
                    row.get(0)?,
                    row.get(1)?,
                    row.get(2)?,
                    row.get(3)?,
                    row.get(4)?,
                    row.get(5)?,
                    row.get(6)?,
                    row.get(7)?,
                ))
            },
        );

        let (id, name, settings_config_str, _row_category, created_at, sort_index, notes, meta_str) =
            match row_data {
                Ok(v) => v,
                Err(rusqlite::Error::QueryReturnedNoRows) => return Ok(None),
                Err(e) => return Err(AppError::Database(e.to_string())),
            };

        let settings_config = serde_json::from_str(&settings_config_str).map_err(|e| {
            AppError::Database(format!(
                "Failed to parse {category} provider settings_config (provider_id={id}): {e}"
            ))
        })?;
        let meta: crate::provider::ProviderMeta = if meta_str.trim().is_empty() {
            crate::provider::ProviderMeta::default()
        } else {
            serde_json::from_str(&meta_str).map_err(|e| {
                AppError::Database(format!(
                    "Failed to parse {category} provider meta (provider_id={id}): {e}"
                ))
            })?
        };

        Ok(Some(Provider {
            id,
            name,
            settings_config,
            website_url: None,
            category: Some(category.to_string()),
            created_at,
            sort_index,
            notes,
            meta: Some(meta),
            icon: None,
            icon_color: None,
            in_failover_queue: false,
        }))
    }
}