use super::{DataProvider, ProviderError, User};
use bcrypt::verify;
use postgres::{Client, NoTls};
use std::path::PathBuf;

/// PostgreSQL 数据提供者（兼容 SFTPGo 的 users 表）
pub struct PgProvider {
    conn_str: String,
}

impl PgProvider {
    /// 从连接字符串创建 PgProvider
    ///
    /// 连接字符串格式：host=127.0.0.1 port=5432 dbname=sftpgo user=sftpgo password=sftpgo_pass_2026
    pub fn new(conn_str: &str) -> Result<Self, ProviderError> {
        Ok(Self {
            conn_str: conn_str.to_string(),
        })
    }

    pub fn from_params(
        host: &str,
        port: u16,
        dbname: &str,
        user: &str,
        password: &str,
    ) -> Result<Self, ProviderError> {
        let conn_str = format!(
            "host={} port={} dbname={} user={} password={}",
            host, port, dbname, user, password
        );
        Ok(Self { conn_str })
    }

    fn open_conn(&self) -> Result<Client, ProviderError> {
        Client::connect(&self.conn_str, NoTls)
            .map_err(|e| ProviderError::Internal(format!("PostgreSQL connect failed: {}", e)))
    }
}

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

        let result = conn
            .query_opt(
                "SELECT username, password, home_dir, permissions, uid, gid, status
             FROM users WHERE username = $1 AND status = 1",
                &[&username],
            )
            .map_err(|e| ProviderError::Internal(format!("Query error: {}", e)))?;

        match result {
            Some(row) => Ok(Some(User {
                username: row.get(0),
                password_hash: row.get::<_, Option<String>>(1).unwrap_or_default(),
                home_dir: PathBuf::from(row.get::<_, String>(2)),
                permissions: row
                    .get::<_, Option<String>>(3)
                    .unwrap_or_else(|| "*".to_string()),
                uid: row.get::<_, i64>(4) as u32,
                gid: row.get::<_, i64>(5) as u32,
                status: row.get(6),
            })),
            None => Ok(None),
        }
    }

    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),
        };

        if hash.is_empty() {
            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 mut conn = self.open_conn()?;
        let result = conn
            .query_opt(
                "SELECT public_keys FROM users WHERE username = $1 AND status = 1",
                &[&username],
            )
            .map_err(|e| ProviderError::Internal(format!("Query error: {}", e)))?;

        match result {
            Some(row) => {
                let json_str: Option<String> = row.get(0);
                match json_str {
                    Some(s) if !s.is_empty() => {
                        let keys: Vec<serde_json::Value> =
                            serde_json::from_str(&s).map_err(|e| {
                                ProviderError::Internal(format!("JSON parse error: {}", e))
                            })?;
                        Ok(keys
                            .iter()
                            .filter_map(|v| v.get("public_key")?.as_str().map(|s| s.to_string()))
                            .collect())
                    }
                    _ => Ok(Vec::new()),
                }
            }
            None => Ok(Vec::new()),
        }
    }
}

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

    #[test]
    fn test_pg_provider_connection() {
        // 仅当 SFTPGo PostgreSQL 可用时运行
        let provider = PgProvider::new(
            "host=127.0.0.1 port=5432 dbname=sftpgo user=sftpgo password=sftpgo_pass_2026",
        );
        assert!(provider.is_ok(), "Should connect to SFTPGo PostgreSQL");
    }

    #[test]
    fn test_pg_get_user_demo() {
        let provider = PgProvider::new(
            "host=127.0.0.1 port=5432 dbname=sftpgo user=sftpgo password=sftpgo_pass_2026",
        )
        .unwrap();
        let user = provider.get_user("demo").unwrap();
        assert!(user.is_some(), "Demo user should exist");
        assert_eq!(user.unwrap().username, "demo");
    }

    #[test]
    fn test_pg_get_user_momentry() {
        let provider = PgProvider::new(
            "host=127.0.0.1 port=5432 dbname=sftpgo user=sftpgo password=sftpgo_pass_2026",
        )
        .unwrap();
        let user = provider.get_user("momentry").unwrap();
        assert!(user.is_some(), "Momentry user should exist");
    }

    #[test]
    fn test_pg_get_user_warren() {
        let provider = PgProvider::new(
            "host=127.0.0.1 port=5432 dbname=sftpgo user=sftpgo password=sftpgo_pass_2026",
        )
        .unwrap();
        let user = provider.get_user("warren").unwrap();
        assert!(user.is_some(), "Warren user should exist");
    }

    #[test]
    fn test_pg_check_password_demo() {
        let provider = PgProvider::new(
            "host=127.0.0.1 port=5432 dbname=sftpgo user=sftpgo password=sftpgo_pass_2026",
        )
        .unwrap();
        let valid = provider.check_password("demo", "demo123").unwrap();
        assert!(valid, "Password should be valid");
    }

    #[test]
    fn test_pg_check_password_invalid() {
        let provider = PgProvider::new(
            "host=127.0.0.1 port=5432 dbname=sftpgo user=sftpgo password=sftpgo_pass_2026",
        )
        .unwrap();
        let valid = provider.check_password("demo", "wrong").unwrap();
        assert!(!valid, "Wrong password should fail");
    }

    #[test]
    fn test_pg_get_home_dir() {
        let provider = PgProvider::new(
            "host=127.0.0.1 port=5432 dbname=sftpgo user=sftpgo password=sftpgo_pass_2026",
        )
        .unwrap();
        let dir = provider.get_home_dir("demo").unwrap();
        assert!(dir.is_some());
        assert!(dir.unwrap().contains("momentry"));
    }

    #[test]
    fn test_pg_nonexistent_user() {
        let provider = PgProvider::new(
            "host=127.0.0.1 port=5432 dbname=sftpgo user=sftpgo password=sftpgo_pass_2026",
        )
        .unwrap();
        let user = provider.get_user("__nonexistent__").unwrap();
        assert!(user.is_none());
    }
}