package main

import (
	"flag"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"strings"

	"go.uber.org/zap"

	"skeleton/config"
	"skeleton/database"
	"skeleton/middlewares"
)

func main() {
	var (
		env    = flag.String("env", "", "Atlas 环境，默认根据应用环境和数据库驱动推断")
		action = flag.String("action", "", "操作类型: status, diff, apply, validate, reset, baseline")
		name   = flag.String("name", "", "迁移名称 (仅用于 diff 操作)")
		dryRun = flag.Bool("dry-run", false, "模拟执行，不实际应用迁移 (仅用于 apply 操作)")
	)
	flag.Parse()

	if *action == "" {
		printUsage()
		os.Exit(1)
	}

	if err := database.EnsureAtlasInstalled(); err != nil {
		log.Fatal("Atlas CLI 未安装:", err)
	}

	cfg, err := config.Load()
	if err != nil {
		log.Fatal("加载配置失败:", err)
	}

	if err := middlewares.InitLogger(&cfg.Logger); err != nil {
		log.Fatal("初始化日志系统失败:", err)
	}
	defer middlewares.Sync()

	driver := normalizeDriver(cfg.Database.Driver)
	if driver != "postgres" && driver != "mysql" && driver != "sqlite" {
		middlewares.Logger.Fatal("不支持的数据库驱动", zap.String("driver", cfg.Database.Driver))
	}
	if *env == "" {
		*env = atlasEnvironment(cfg.App.Environment, driver)
	}

	migrationConfig := &database.MigrationConfig{
		Environment: *env,
		Directory:   filepath.Join("migrations", driver),
		Timeout:     240,
	}

	manager := database.NewMigrationManager(migrationConfig, middlewares.Logger)

	if err := manager.InitMigrationDirectory(); err != nil {
		middlewares.Logger.Fatal("初始化迁移目录失败", zap.Error(err))
	}

	switch *action {
	case "status":
		handleStatus(manager)
	case "diff":
		handleDiff(manager, *name)
	case "apply":
		handleApply(manager, *dryRun)
	case "validate":
		handleValidate(manager)
	case "reset":
		handleReset()
	case "baseline":
		handleBaseline(*env)
	default:
		fmt.Printf("未知操作: %s\n", *action)
		printUsage()
		os.Exit(1)
	}
}

func normalizeDriver(driver string) string {
	switch strings.ToLower(strings.TrimSpace(driver)) {
	case "postgresql":
		return "postgres"
	case "sqlite3":
		return "sqlite"
	default:
		return strings.ToLower(strings.TrimSpace(driver))
	}
}

func atlasEnvironment(environment, driver string) string {
	prefix := "local"
	if strings.EqualFold(environment, "production") {
		prefix = "production"
	}
	return prefix + "_" + driver
}

func handleStatus(manager *database.MigrationManager) {
	fmt.Println("🔍 检查迁移状态...")
	if err := manager.CheckMigrations(); err != nil {
		middlewares.Logger.Fatal("检查迁移状态失败", zap.Error(err))
	}
	fmt.Println("✅ 迁移状态检查完成")
}

func handleDiff(manager *database.MigrationManager, name string) {
	if name == "" {
		fmt.Println("📝 生成迁移文件...")
	} else {
		fmt.Printf("📝 生成迁移文件: %s\n", name)
	}

	if err := manager.GenerateMigration(name); err != nil {
		middlewares.Logger.Fatal("生成迁移失败", zap.Error(err))
	}
	fmt.Println("✅ 迁移文件生成完成")
}

func handleApply(manager *database.MigrationManager, dryRun bool) {
	if dryRun {
		fmt.Println("🧪 模拟应用迁移 (dry-run)...")
	} else {
		fmt.Println("🚀 应用迁移...")
	}

	if err := manager.ApplyMigrations(dryRun); err != nil {
		middlewares.Logger.Fatal("应用迁移失败", zap.Error(err))
	}
	fmt.Println("✅ 迁移应用完成")
}

func handleValidate(manager *database.MigrationManager) {
	fmt.Println("🔍 验证迁移文件...")
	if err := manager.ValidateMigrations(); err != nil {
		middlewares.Logger.Fatal("验证迁移失败", zap.Error(err))
	}
	fmt.Println("✅ 迁移验证通过")
}

func handleReset() {
	fmt.Println("⚠️  重置迁移历史是危险操作!")
	fmt.Println("请手动执行: atlas migrate reset --env [环境名]")
	fmt.Println("这将删除迁移历史表，请谨慎操作")
}

func handleBaseline(env string) {
	fmt.Println("📍 基线迁移指导")
	fmt.Println()
	fmt.Println("基线迁移用于将现有数据库纳入迁移管理。请根据你的情况选择合适的方法：")
	fmt.Println()

	fmt.Println("🔄 情况1 - 全新数据库:")
	fmt.Printf("  atlas migrate diff baseline --env %s\n", env)
	fmt.Printf("  go run cmd/migrate/main.go -action apply -env %s\n", env)
	fmt.Println()

	fmt.Println("🔄 情况2 - 现有数据库（推荐）:")
	fmt.Printf("  atlas migrate diff baseline --env %s\n", env)
	fmt.Printf("  atlas migrate hash --env %s\n", env)
	fmt.Println("  # 然后应用后续新迁移")
	fmt.Println()

	fmt.Println("🔄 情况3 - 强制重建基线:")
	fmt.Printf("  atlas migrate reset --env %s\n", env)
	fmt.Printf("  go run cmd/migrate/main.go -action diff -name baseline -env %s\n", env)
	fmt.Printf("  go run cmd/migrate/main.go -action apply -env %s\n", env)
	fmt.Println()

	fmt.Println("⚠️  注意事项:")
	fmt.Println("  - 在生产环境操作前请务必备份数据库")
	fmt.Println("  - 确保团队成员都从同一基线开始")
	fmt.Println("  - 建议先在开发环境测试迁移流程")
}

func printUsage() {
	fmt.Println("数据库迁移管理工具")
	fmt.Println()
	fmt.Println("用法:")
	fmt.Println("  go run cmd/migrate/main.go -action <操作> [选项]")
	fmt.Println()
	fmt.Println("操作:")
	fmt.Println("  status    检查迁移状态")
	fmt.Println("  diff      生成迁移文件 (可选: -name <迁移名称>)")
	fmt.Println("  apply     应用迁移 (可选: -dry-run)")
	fmt.Println("  validate  验证迁移文件")
	fmt.Println("  reset     重置迁移历史 (仅显示提示)")
	fmt.Println("  baseline  基线迁移指导 (显示基线创建命令)")
	fmt.Println()
	fmt.Println("选项:")
	fmt.Println("  -env      Atlas 环境 (默认: local_<driver> 或 production_<driver>)")
	fmt.Println("  -name     迁移名称 (仅用于 diff)")
	fmt.Println("  -dry-run  模拟执行 (仅用于 apply)")
	fmt.Println()
	fmt.Println("示例:")
	fmt.Println("  go run cmd/migrate/main.go -action status")
	fmt.Println("  go run cmd/migrate/main.go -action diff -name create_users")
	fmt.Println("  go run cmd/migrate/main.go -action apply")
	fmt.Println("  go run cmd/migrate/main.go -action apply -dry-run")
	fmt.Println("  go run cmd/migrate/main.go -action validate")
	fmt.Println("  go run cmd/migrate/main.go -action baseline")
}