package postgres

import (
	"database/sql"
	"fmt"
	"time"

	_ "github.com/lib/pq"
)

// DB 数据库连接包装器
type DB struct {
	conn *sql.DB
}

// NewDB 创建新的数据库连接
func NewDB(connString string) (*DB, error) {
	if connString == "" {
		return nil, fmt.Errorf("database connection string cannot be empty")
	}

	conn, err := sql.Open("postgres", connString)
	if err != nil {
		return nil, fmt.Errorf("failed to open database: %w", err)
	}

	// 配置连接池
	conn.SetMaxOpenConns(25)
	conn.SetMaxIdleConns(5)
	conn.SetConnMaxLifetime(5 * time.Minute)

	// 测试连接
	if err := conn.Ping(); err != nil {
		return nil, fmt.Errorf("failed to ping database: %w", err)
	}

	return &DB{conn: conn}, nil
}

// Close 关闭数据库连接
func (db *DB) Close() error {
	if db.conn != nil {
		return db.conn.Close()
	}
	return nil
}

// GetConn 获取底层连接（用于事务等高级操作）
func (db *DB) GetConn() *sql.DB {
	return db.conn
}

// InitSchema 初始化数据库 schema
func (db *DB) InitSchema() error {
	schema := `
		-- Users 表
		CREATE TABLE IF NOT EXISTS users (
			id VARCHAR(36) PRIMARY KEY,
			username VARCHAR(255) NOT NULL UNIQUE,
			password_hash TEXT NOT NULL,
			email VARCHAR(255) NOT NULL,
			created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
			updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
		);

		CREATE INDEX IF NOT EXISTS idx_users_username ON users(username);

		-- Clusters 表
		CREATE TABLE IF NOT EXISTS clusters (
			id VARCHAR(36) PRIMARY KEY,
			name VARCHAR(255) NOT NULL UNIQUE,
			host TEXT NOT NULL,
			ca_data TEXT,
			cert_data TEXT,
			key_data TEXT,
			token TEXT,
			description TEXT,
			created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
			updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
		);

		CREATE INDEX IF NOT EXISTS idx_clusters_name ON clusters(name);

		-- Registries 表
		CREATE TABLE IF NOT EXISTS registries (
			id VARCHAR(36) PRIMARY KEY,
			name VARCHAR(255) NOT NULL UNIQUE,
			url TEXT NOT NULL,
			description TEXT,
			username VARCHAR(255),
			password TEXT,
			insecure BOOLEAN DEFAULT FALSE,
			created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
			updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
		);

		CREATE INDEX IF NOT EXISTS idx_registries_name ON registries(name);

		-- Instances 表
		CREATE TABLE IF NOT EXISTS instances (
			id VARCHAR(36) PRIMARY KEY,
			cluster_id VARCHAR(36) NOT NULL,
			name VARCHAR(255) NOT NULL,
			namespace VARCHAR(255) NOT NULL,
			registry_id VARCHAR(36) NOT NULL,
			repository TEXT NOT NULL,
			chart VARCHAR(255) NOT NULL,
			version VARCHAR(255) NOT NULL,
			description TEXT,
			values JSONB,
			values_yaml TEXT,
			status VARCHAR(50) NOT NULL,
			status_reason TEXT,
			last_operation VARCHAR(50),
			last_error TEXT,
			revision INTEGER NOT NULL DEFAULT 1,
			created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
			updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
			CONSTRAINT fk_cluster FOREIGN KEY (cluster_id) REFERENCES clusters(id) ON DELETE CASCADE,
			CONSTRAINT fk_registry FOREIGN KEY (registry_id) REFERENCES registries(id) ON DELETE CASCADE,
			CONSTRAINT unique_cluster_name UNIQUE (cluster_id, name, namespace)
		);

		CREATE INDEX IF NOT EXISTS idx_instances_cluster ON instances(cluster_id);
		CREATE INDEX IF NOT EXISTS idx_instances_registry ON instances(registry_id);
		CREATE INDEX IF NOT EXISTS idx_instances_name ON instances(name);
	`

	_, err := db.conn.Exec(schema)
	if err != nil {
		return fmt.Errorf("failed to initialize schema: %w", err)
	}

	return nil
}