package db

import (
	"fmt"
	"time"

	"github.com/langgenius/dify-plugin-daemon/internal/types/app"
	"github.com/langgenius/dify-plugin-daemon/internal/types/models"
	"github.com/langgenius/dify-plugin-daemon/internal/utils/log"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
)

func initDifyPluginDB(host string, port int, db_name string, default_db_name string, user string, pass string, sslmode string) error {
	// first try to connect to target database
	dsn := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=%s", host, port, user, pass, db_name, sslmode)
	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
	if err != nil {
		// if connection fails, try to create database
		dsn = fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=%s", host, port, user, pass, default_db_name, sslmode)
		db, err = gorm.Open(postgres.Open(dsn), &gorm.Config{})
		if err != nil {
			return err
		}

		pgsqlDB, err := db.DB()
		if err != nil {
			return err
		}
		defer pgsqlDB.Close()

		// check if the db exists
		rows, err := pgsqlDB.Query(fmt.Sprintf("SELECT 1 FROM pg_database WHERE datname = '%s'", db_name))
		if err != nil {
			return err
		}

		if !rows.Next() {
			// create database
			_, err = pgsqlDB.Exec(fmt.Sprintf("CREATE DATABASE %s", db_name))
			if err != nil {
				return err
			}
		}

		// connect to the new db
		dsn = fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=%s", host, port, user, pass, db_name, sslmode)
		db, err = gorm.Open(postgres.Open(dsn), &gorm.Config{})
		if err != nil {
			return err
		}
	}

	pgsqlDB, err := db.DB()
	if err != nil {
		return err
	}

	// check if uuid-ossp extension exists
	rows, err := pgsqlDB.Query("SELECT 1 FROM pg_extension WHERE extname = 'uuid-ossp'")
	if err != nil {
		return err
	}

	if !rows.Next() {
		// create the uuid-ossp extension
		_, err = pgsqlDB.Exec("CREATE EXTENSION IF NOT EXISTS \"uuid-ossp\"")
		if err != nil {
			return err
		}
	}

	pgsqlDB.SetConnMaxIdleTime(time.Minute * 1)
	DifyPluginDB = db

	return nil
}

func autoMigrate() error {
	err := DifyPluginDB.AutoMigrate(
		models.Plugin{},
		models.PluginInstallation{},
		models.PluginDeclaration{},
		models.Endpoint{},
		models.ServerlessRuntime{},
		models.ToolInstallation{},
		models.AIModelInstallation{},
		models.InstallTask{},
		models.TenantStorage{},
		models.AgentStrategyInstallation{},
	)

	if err != nil {
		return err
	}

	// check if "declaration" table exists in Plugin/ServerlessRuntime/ToolInstallation/AIModelInstallation/AgentStrategyInstallation
	// delete the column if exists
	ignoreDeclarationColumn := func(table string) error {
		if DifyPluginDB.Migrator().HasColumn(table, "declaration") {
			// remove NOT NULL constraint on declaration column
			if err := DifyPluginDB.Exec("ALTER TABLE " + table + " ALTER COLUMN declaration DROP NOT NULL").Error; err != nil {
				return err
			}
		}
		return nil
	}

	if err := ignoreDeclarationColumn("plugins"); err != nil {
		return err
	}

	if err := ignoreDeclarationColumn("serverless_runtimes"); err != nil {
		return err
	}

	if err := ignoreDeclarationColumn("tool_installations"); err != nil {
		return err
	}

	if err := ignoreDeclarationColumn("ai_model_installations"); err != nil {
		return err
	}

	if err := ignoreDeclarationColumn("agent_strategy_installations"); err != nil {
		return err
	}

	return nil
}

func Init(config *app.Config) {
	err := initDifyPluginDB(
		config.DBHost,
		int(config.DBPort),
		config.DBDatabase,
		"postgres",
		config.DBUsername,
		config.DBPassword,
		config.DBSslMode,
	)

	if err != nil {
		log.Panic("failed to init dify plugin db: %v", err)
	}

	err = autoMigrate()
	if err != nil {
		log.Panic("failed to auto migrate: %v", err)
	}

	log.Info("dify plugin db initialized")
}

func Close() {
	db, err := DifyPluginDB.DB()
	if err != nil {
		log.Error("failed to close dify plugin db: %v", err)
		return
	}

	err = db.Close()
	if err != nil {
		log.Error("failed to close dify plugin db: %v", err)
		return
	}

	log.Info("dify plugin db closed")
}