package main

import (
	"context"

	"forge.cadoles.com/Cadoles/guesstimate/internal/model"
	"forge.cadoles.com/Cadoles/guesstimate/internal/orm"
	"github.com/jinzhu/gorm"
	"github.com/pkg/errors"
	"gitlab.com/wpetit/goweb/logger"
	"gitlab.com/wpetit/goweb/service"
)

const (
	migrateUp     = "up"
	migrateLatest = "latest"
	migrateDown   = "down"
)

func applyMigration(ctx context.Context, ctn *service.Container) error {
	orm, err := orm.From(ctn)
	if err != nil {
		return err
	}

	migr := orm.Migration()

	// Register available migrations
	migr.Register(
		m000initialSchema(),
	)

	currentVersion, err := migr.CurrentVersion(ctx)
	if err != nil {
		return errors.Wrap(err, "could not retrieve current data schema version")
	}

	switch migrate {
	case migrateUp:
		if err := migr.Up(ctx); err != nil {
			return errors.Wrap(err, "could not apply up migration")
		}

	case migrateLatest:
		latestVersion, err := migr.LatestVersion()
		if err != nil {
			return errors.Wrap(err, "could not retrieve latest data schema version")
		}

		logger.Info(
			ctx,
			"migrating data schema to latest version",
			logger.F("currentVersion", currentVersion),
			logger.F("latestVersion", latestVersion),
		)

		// Execute migration to latest available version
		if err := migr.Latest(ctx); err != nil {
			return errors.Wrap(err, "could not migrate to latest data schema")
		}

	case migrateDown:
		if err := migr.Down(ctx); err != nil {
			return errors.Wrap(err, "could not apply down migration")
		}

	default:
		return errors.Errorf("unknown migration command: '%s'", migrate)
	}

	logger.Info(
		ctx,
		"migration completed",
	)

	return nil
}

// nolint: gochecknoglobals
var initialModels = []interface{}{
	&model.User{},
	&model.Project{},
	&model.Access{},
	&model.TaskCategory{},
	&model.Task{},
}

func m000initialSchema() orm.Migration {
	return orm.NewDBMigration(
		"00_initial_schema",
		func(ctx context.Context, tx *gorm.DB) error {
			for _, m := range initialModels {
				if err := tx.AutoMigrate(m).Error; err != nil {
					return errors.WithStack(err)
				}
			}

			// Create foreign keys indexes
			err := tx.Model(&model.Access{}).
				AddForeignKey("user_id", "users(id)", "CASCADE", "CASCADE").Error
			if err != nil {
				return errors.WithStack(err)
			}

			err = tx.Model(&model.TaskCategory{}).
				AddForeignKey("project_id", "projects(id)", "CASCADE", "CASCADE").Error
			if err != nil {
				return errors.WithStack(err)
			}

			err = tx.Model(&model.Access{}).
				AddForeignKey("project_id", "projects(id)", "CASCADE", "CASCADE").Error
			if err != nil {
				return errors.WithStack(err)
			}

			err = tx.Model(&model.Access{}).
				AddForeignKey("user_id", "users(id)", "CASCADE", "CASCADE").Error
			if err != nil {
				return errors.WithStack(err)
			}

			err = tx.Model(&model.Task{}).
				AddForeignKey("category_id", "task_categories(id)", "CASCADE", "CASCADE").Error
			if err != nil {
				return errors.WithStack(err)
			}

			return nil
		},
		func(ctx context.Context, tx *gorm.DB) error {
			for i := len(initialModels) - 1; i >= 0; i-- {
				if err := tx.DropTableIfExists(initialModels[i]).Error; err != nil {
					return errors.WithStack(err)
				}
			}

			if err := tx.DropTableIfExists("sessions").Error; err != nil {
				return errors.WithStack(err)
			}

			return nil
		},
	)
}