// Command migrate manages database migrations.
//
// Usage:
//
//	go run ./cmd/migrate up        apply all pending migrations
//	go run ./cmd/migrate down      roll back the most recent group
//	go run ./cmd/migrate status    list migrations and whether they ran
//	go run ./cmd/migrate new NAME  create a Go migration scaffold named
//	                                <timestamp>_NAME.go in
//	                                internal/database/migrations/
package main

import (
	"context"
	"fmt"
	"os"

	_ "github.com/joho/godotenv/autoload"

	"git.k6n.net/mats/fullstack-template/internal/config"
	"git.k6n.net/mats/fullstack-template/internal/database"
)

func main() {
	cmd := "up"
	if len(os.Args) > 1 {
		cmd = os.Args[1]
	}
	if cmd != "up" && cmd != "down" && cmd != "status" && cmd != "new" {
		fmt.Fprintln(os.Stderr, "usage: migrate [up|down|status|new NAME]")
		os.Exit(2)
	}

	cfg, err := config.Load()
	if err != nil {
		fatal(err)
	}
	db, err := database.Open(cfg)
	if err != nil {
		fatal(err)
	}
	defer db.Close()

	ctx := context.Background()
	m := database.NewMigrator(db)

	switch cmd {
	case "up":
		if err := m.Init(ctx); err != nil {
			fatal(err)
		}
		group, err := m.Migrate(ctx)
		if err != nil {
			fatal(err)
		}
		if group.IsZero() {
			fmt.Println("no pending migrations")
		} else {
			fmt.Printf("applied %d migration(s) (group %d)\n", len(group.Migrations), group.ID)
		}
	case "down":
		if err := m.Init(ctx); err != nil {
			fatal(err)
		}
		group, err := m.Rollback(ctx)
		if err != nil {
			fatal(err)
		}
		if group.IsZero() {
			fmt.Println("nothing to roll back")
		} else {
			fmt.Printf("rolled back %d migration(s) (group %d)\n", len(group.Migrations), group.ID)
		}
	case "status":
		if err := m.Init(ctx); err != nil {
			fatal(err)
		}
		migrations, err := m.MigrationsWithStatus(ctx)
		if err != nil {
			fatal(err)
		}
		for _, mig := range migrations {
			state := "pending"
			if mig.IsApplied() {
				state = "applied"
			}
			fmt.Printf("%-8s %s %s\n", state, mig.Name, mig.Comment)
		}
	case "new":
		if len(os.Args) < 3 {
			fmt.Fprintln(os.Stderr, "usage: migrate new NAME (snake_case)")
			os.Exit(2)
		}
		file, err := m.CreateGoMigration(ctx, os.Args[2])
		if err != nil {
			fatal(err)
		}
		fmt.Println("created", file.Path)
	}
}

func fatal(err error) {
	fmt.Fprintln(os.Stderr, "migrate:", err)
	os.Exit(1)
}