//
//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
//

package dao

import (
	"fmt"
	"ragflow/internal/model"
	"ragflow/internal/server"
	"time"

	gormLogger "gorm.io/gorm/logger"

	"gorm.io/driver/mysql"
	"gorm.io/gorm"

	"ragflow/internal/logger"
)

var DB *gorm.DB

// InitDB initialize database connection
func InitDB() error {
	cfg := server.GetConfig()
	dbCfg := cfg.Database

	dsn := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=%s&parseTime=True&loc=Local",
		dbCfg.Username,
		dbCfg.Password,
		dbCfg.Host,
		dbCfg.Port,
		dbCfg.Database,
		dbCfg.Charset,
	)

	// Set log level
	var gormLogLevel gormLogger.LogLevel
	if cfg.Server.Mode == "debug" {
		gormLogLevel = gormLogger.Info
	} else {
		gormLogLevel = gormLogger.Silent
	}

	// Connect to database
	var err error
	DB, err = gorm.Open(mysql.Open(dsn), &gorm.Config{
		Logger: gormLogger.Default.LogMode(gormLogLevel),
		NowFunc: func() time.Time {
			return time.Now().Local()
		},
	})
	if err != nil {
		return fmt.Errorf("failed to connect database: %w", err)
	}

	// Get general database object sql.DB
	sqlDB, err := DB.DB()
	if err != nil {
		return fmt.Errorf("failed to get database instance: %w", err)
	}

	// Set connection pool
	sqlDB.SetMaxIdleConns(10)
	sqlDB.SetMaxOpenConns(100)
	sqlDB.SetConnMaxLifetime(time.Hour)

	// Auto migrate all models
	models := []interface{}{
		&model.User{},
		&model.Tenant{},
		&model.UserTenant{},
		&model.File{},
		&model.File2Document{},
		&model.TenantLLM{},
		&model.Chat{},
		&model.ChatSession{},
		&model.Task{},
		&model.APIToken{},
		&model.API4Conversation{},
		&model.Knowledgebase{},
		&model.InvitationCode{},
		&model.Document{},
		&model.UserCanvas{},
		&model.CanvasTemplate{},
		&model.UserCanvasVersion{},
		&model.LLMFactories{},
		&model.LLM{},
		&model.TenantLangfuse{},
		&model.SystemSettings{},
		&model.Connector{},
		&model.Connector2Kb{},
		&model.SyncLogs{},
		&model.MCPServer{},
		&model.Memory{},
		&model.Search{},
		&model.PipelineOperationLog{},
		&model.EvaluationDataset{},
		&model.EvaluationCase{},
		&model.EvaluationRun{},
		&model.EvaluationResult{},
	}

	for _, m := range models {
		if err := DB.AutoMigrate(m); err != nil {
			return fmt.Errorf("failed to migrate model %T: %w", m, err)
		}
	}

	// Run manual migrations for complex schema changes
	if err := RunMigrations(DB); err != nil {
		return fmt.Errorf("failed to run manual migrations: %w", err)
	}

	logger.Info("Database connected and migrated successfully")
	return nil
}

// GetDB get database instance
func GetDB() *gorm.DB {
	return DB
}