use std::path::PathBuf;
use rusqlite::{Connection, params};
use bcrypt::verify;
use super::{DataProvider, ProviderError, User};

/// SQLite 数据提供者
pub struct SqliteProvider {
    db_path: PathBuf,
}

impl SqliteProvider {
    pub fn new(db_path: &str) -> Result<Self, ProviderError> {
        let path = PathBuf::from(db_path);
        if !path.exists() {
            return Err(ProviderError::NotFound(format!(
                "Database not found: {}", db_path
            )));
        }
        Ok(Self { db_path: path })
    }

    fn open_conn(&self) -> Result<Connection, ProviderError> {
        Connection::open(&self.db_path)
            .map_err(|e| ProviderError::Internal(format!("Failed to open database: {}", e)))
    }
}

impl DataProvider for SqliteProvider {
    fn get_user(&self, username: &str) -> Result<Option<User>, ProviderError> {
        let conn = self.open_conn()?;

        let result = conn.query_row(
            "SELECT username, password_hash, home_dir, permissions, uid, gid, status
             FROM sftpgo_users WHERE username = ?1 AND status = 1",
            params![username],
            |row| {
                Ok(User {
                    username: row.get(0)?,
                    password_hash: row.get(1)?,
                    home_dir: PathBuf::from(row.get::<_, String>(2)?),
                    permissions: row.get(3)?,
                    uid: row.get::<_, i64>(4)? as u32,
                    gid: row.get::<_, i64>(5)? as u32,
                    status: row.get(6)?,
                })
            },
        );

        match result {
            Ok(user) => Ok(Some(user)),
            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(None),
            Err(e) => Err(ProviderError::Internal(format!(
                "Database query error: {}", e
            ))),
        }
    }

    fn check_password(&self, username: &str, password: &str) -> Result<bool, ProviderError> {
        let hash = match self.get_user(username)? {
            Some(user) => user.password_hash,
            None => return Ok(false),
        };

        verify(password, &hash)
            .map_err(|e| ProviderError::Internal(format!("bcrypt verify error: {}", e)))
    }

    fn get_home_dir(&self, username: &str) -> Result<Option<String>, ProviderError> {
        Ok(self.get_user(username)?.map(|u| u.home_dir.to_string_lossy().to_string()))
    }

    fn get_public_keys(&self, username: &str) -> Result<Vec<String>, ProviderError> {
        let _ = username;
        Ok(Vec::new())
    }

    fn get_user_groups(&self, username: &str) -> Result<Vec<String>, ProviderError> {
        let conn = self.open_conn()?;
        let groups: Vec<String> = conn
            .prepare("SELECT group_name FROM users_groups_mapping WHERE username = ?1")
            .map_err(|e| ProviderError::Internal(format!("Query prepare error: {}", e)))?
            .query_map(params![username], |row| row.get(0))
            .map_err(|e| ProviderError::Internal(format!("Query map error: {}", e)))?
            .filter_map(|r| r.ok())
            .collect();
        Ok(groups)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_provider_not_found() {
        let provider = SqliteProvider::new("/tmp/nonexistent.db");
        assert!(provider.is_err());
    }

    #[test]
    fn test_provider_get_user() {
        let provider = SqliteProvider::new("data/auth.sqlite").unwrap();
        let user = provider.get_user("demo").unwrap();
        assert!(user.is_some());
        assert_eq!(user.unwrap().username, "demo");
    }

    #[test]
    fn test_provider_nonexistent_user() {
        let provider = SqliteProvider::new("data/auth.sqlite").unwrap();
        let user = provider.get_user("__nonexistent__").unwrap();
        assert!(user.is_none());
    }

    #[test]
    fn test_check_password_valid() {
        let provider = SqliteProvider::new("data/auth.sqlite").unwrap();
        let valid = provider.check_password("demo", "demo123").unwrap();
        assert!(valid);
    }

    #[test]
    fn test_check_password_invalid() {
        let provider = SqliteProvider::new("data/auth.sqlite").unwrap();
        let valid = provider.check_password("demo", "wrong").unwrap();
        assert!(!valid);
    }

    #[test]
    fn test_get_home_dir() {
        let provider = SqliteProvider::new("data/auth.sqlite").unwrap();
        let dir = provider.get_home_dir("demo").unwrap();
        assert!(dir.is_some());
    }
}