use crate::application::errors::RepositoryError;
use crate::application::traits::DictRepository;
use crate::core::entities::{Dict, DictEntry, DictEntryId};
use sqlx::{Row, SqlitePool, sqlite::SqliteConnectOptions};
use std::collections::HashMap;
use std::str::FromStr;

#[derive(Clone)]
pub struct SqliteDictRepository {
    pool: SqlitePool,
}

impl SqliteDictRepository {
    pub async fn new(database_url: &str) -> Result<Self, RepositoryError> {
        let options = SqliteConnectOptions::from_str(database_url)
            .map_err(|_| RepositoryError::ConnectionFailed)?
            .create_if_missing(true);

        let pool = SqlitePool::connect_with(options)
            .await
            .map_err(|_| RepositoryError::ConnectionFailed)?;

        // Run migrations
        sqlx::migrate!("./migrations")
            .run(&pool)
            .await
            .map_err(|e| RepositoryError::Unexpected(format!("Failed to run migrations: {}", e)))?;

        Ok(Self { pool })
    }

    async fn ensure_dict_tables(&self, dict_name: &str) -> Result<(), RepositoryError> {
        // Create dict table if not exists
        sqlx::query(
            r#"
            CREATE TABLE IF NOT EXISTS dicts (
                name TEXT PRIMARY KEY,
                created_at DATETIME DEFAULT CURRENT_TIMESTAMP
            )
            "#,
        )
        .execute(&self.pool)
        .await
        .map_err(|_| RepositoryError::ConnectionFailed)?;

        // Insert dict if not exists
        sqlx::query("INSERT OR IGNORE INTO dicts (name) VALUES (?)")
            .bind(dict_name)
            .execute(&self.pool)
            .await
            .map_err(|_| RepositoryError::ConnectionFailed)?;

        // Create entries table for this dict
        let table_name = format!("dict_entries_{}", dict_name);
        let create_table_sql = format!(
            r#"
            CREATE TABLE IF NOT EXISTS {} (
                id INTEGER PRIMARY KEY,
                text TEXT NOT NULL UNIQUE,
                metadata TEXT,
                created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
                updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
            )
            "#,
            table_name
        );

        sqlx::query(&create_table_sql)
            .execute(&self.pool)
            .await
            .map_err(|_| RepositoryError::ConnectionFailed)?;

        Ok(())
    }

    pub fn get_next_id(&self, dict_name: &str) -> Result<u32, RepositoryError> {
        let pool = self.pool.clone();
        let dict_name = dict_name.to_string();

        tokio::task::block_in_place(|| {
            tokio::runtime::Handle::current().block_on(async move {
                let table_name = format!("dict_entries_{}", dict_name);

                let result: Option<i64> =
                    sqlx::query_scalar(&format!("SELECT MAX(id) FROM {}", table_name))
                        .fetch_one(&pool)
                        .await
                        .map_err(|_| RepositoryError::ConnectionFailed)?;

                Ok(result.map(|id| id as u32 + 1).unwrap_or(1))
            })
        })
    }

    fn find_id_by_text(&self, dict_name: &str, text: &str) -> Result<Option<u32>, RepositoryError> {
        let pool = self.pool.clone();
        let dict_name = dict_name.to_string();
        let text = text.to_string();

        tokio::task::block_in_place(|| {
            tokio::runtime::Handle::current().block_on(async move {
                let table_name = format!("dict_entries_{}", dict_name);

                let result: Option<i64> =
                    sqlx::query_scalar(&format!("SELECT id FROM {} WHERE text = ?", table_name))
                        .bind(&text)
                        .fetch_one(&pool)
                        .await
                        .map_err(|_| RepositoryError::ConnectionFailed)?;

                Ok(result.map(|id| id as u32))
            })
        })
    }
}

impl DictRepository for SqliteDictRepository {
    fn create(&self, name: &str) -> Result<(), RepositoryError> {
        // This is a synchronous method, but we need to run async operations
        // In a real application, you might want to make the trait async or use a blocking executor
        let pool = self.pool.clone();
        let name = name.to_string();

        // Use tokio's block_in_place to run async code in sync context
        tokio::task::block_in_place(|| {
            tokio::runtime::Handle::current().block_on(async move {
                let mut tx = pool.begin().await.map_err(|e| {
                    RepositoryError::Unexpected(format!("Failed to begin transaction: {}", e))
                })?;

                // Create dict table
                sqlx::query(
                    r#"
                    CREATE TABLE IF NOT EXISTS dicts (
                        name TEXT PRIMARY KEY,
                        created_at DATETIME DEFAULT CURRENT_TIMESTAMP
                    )
                    "#,
                )
                .execute(&mut *tx)
                .await
                .map_err(|e| {
                    RepositoryError::Unexpected(format!("Failed to create dicts table: {}", e))
                })?;

                // Insert dict
                sqlx::query("INSERT OR IGNORE INTO dicts (name) VALUES (?)")
                    .bind(&name)
                    .execute(&mut *tx)
                    .await
                    .map_err(|e| {
                        RepositoryError::Unexpected(format!("Failed to insert dict: {}", e))
                    })?;

                // Create entries table for this dict
                let table_name = format!("dict_entries_{}", name);
                let create_table_sql = format!(
                    r#"
                    CREATE TABLE IF NOT EXISTS {} (
                        id INTEGER PRIMARY KEY,
                        text TEXT NOT NULL UNIQUE,
                        metadata TEXT,
                        created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
                        updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
                    )
                    "#,
                    table_name
                );

                sqlx::query(&create_table_sql)
                    .execute(&mut *tx)
                    .await
                    .map_err(|e| {
                        RepositoryError::Unexpected(format!(
                            "Failed to create entries table: {}",
                            e
                        ))
                    })?;

                tx.commit().await.map_err(|e| {
                    RepositoryError::Unexpected(format!("Failed to commit transaction: {}", e))
                })?;
                Ok(())
            })
        })
    }
    fn save_entries(&self, dict_name: &str, entries: &[DictEntry]) -> Result<(), RepositoryError> {
        let pool = self.pool.clone();
        let dict_name = dict_name.to_string();
        let entries = entries.to_vec();

        tokio::task::block_in_place(|| {
            tokio::runtime::Handle::current().block_on(async move {
                let table_name = format!("dict_entries_{}", dict_name);

                for entry in entries {
                    let metadata_json = serde_json::to_string(&entry.metadata)
                        .map_err(|e| RepositoryError::InvalidData(e.to_string()))?;

                    // Check if entry with this text already exists
                    let existing_id: Option<i64> = sqlx::query_scalar(&format!(
                        "SELECT id FROM {} WHERE text = ?",
                        table_name
                    ))
                    .bind(&entry.text)
                    .fetch_optional(&pool)
                    .await
                    .map_err(|e| RepositoryError::Unexpected(format!("Failed to check existing entry: {}", e)))?;

                    if let Some(id) = existing_id {
                        // Update existing entry
                        sqlx::query(&format!(
                            "UPDATE {} SET metadata = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?",
                            table_name
                        ))
                        .bind(metadata_json)
                        .bind(id)
                        .execute(&pool)
                        .await
                        .map_err(|e| RepositoryError::Unexpected(format!("Failed to update entry: {}", e)))?;
                    } else {
                        // Insert new entry
                        sqlx::query(&format!(
                            "INSERT INTO {} (id, text, metadata) VALUES (?, ?, ?)",
                            table_name
                        ))
                        .bind(entry.id as i64)
                        .bind(&entry.text)
                        .bind(metadata_json)
                        .execute(&pool)
                        .await
                        .map_err(|e| RepositoryError::Unexpected(format!("Failed to insert entry: {}", e)))?;
                    }
                }

                Ok(())
            })
        })
    }

    fn get_next_id(&self, dict_name: &str) -> Result<u32, RepositoryError> {
        self.get_next_id(dict_name)
    }

    fn fetch_many(
        &self,
        name: &str,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> Result<Dict, RepositoryError> {
        let pool = self.pool.clone();
        let name = name.to_string();

        tokio::task::block_in_place(|| {
            tokio::runtime::Handle::current().block_on(async move {
                let table_name = format!("dict_entries_{}", name);

                // Check if dict exists
                let dict_exists: bool =
                    sqlx::query_scalar("SELECT EXISTS(SELECT 1 FROM dicts WHERE name = ?)")
                        .bind(&name)
                        .fetch_one(&pool)
                        .await
                        .map_err(|e| {
                            RepositoryError::Unexpected(format!(
                                "Failed to check dict exists: {}",
                                e
                            ))
                        })?;

                if !dict_exists {
                    return Err(RepositoryError::NotFound);
                }

                let mut query = format!("SELECT id, text, metadata FROM {}", table_name);

                if let Some(offset_val) = offset {
                    query.push_str(&format!(" LIMIT {}", limit.unwrap_or(1000)));
                    query.push_str(&format!(" OFFSET {}", offset_val));
                } else if let Some(limit_val) = limit {
                    query.push_str(&format!(" LIMIT {}", limit_val));
                }

                let rows = sqlx::query(&query).fetch_all(&pool).await.map_err(|e| {
                    RepositoryError::Unexpected(format!("Failed to fetch entries: {}", e))
                })?;

                let mut entries = HashMap::new();
                for row in rows {
                    let id: i64 = row.get("id");
                    let text: String = row.get("text");
                    let metadata_json: Option<String> = row.get("metadata");

                    let metadata = if let Some(json) = metadata_json {
                        serde_json::from_str(&json)
                            .map_err(|e| RepositoryError::InvalidData(e.to_string()))?
                    } else {
                        HashMap::new()
                    };

                    let entry = DictEntry {
                        id: id as DictEntryId,
                        text,
                        metadata,
                    };

                    entries.insert(entry.id, entry);
                }

                Ok(Dict { name, entries })
            })
        })
    }
}