package service

import (
	"context"
	"errors"

	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
	applogger "github.com/gochat/gochat/pkg/logger"
)

// EmailChannelMigrationService implements business logic for EmailChannelMigration operations.
// Reference: Chatwoot api/v1/accounts/:account_id/email_channel_migrations — create-only endpoint
// for initiating migration of an email channel from one inbox to another.
type EmailChannelMigrationService struct {
	repo *repository.EmailChannelMigrationRepo
}

// NewEmailChannelMigrationService creates a new EmailChannelMigrationService.
func NewEmailChannelMigrationService(repo *repository.EmailChannelMigrationRepo) *EmailChannelMigrationService {
	return &EmailChannelMigrationService{repo: repo}
}

// Create creates a new email channel migration record.
// Validates that account_id, inbox_id (source), and target_inbox_id are provided.
func (s *EmailChannelMigrationService) Create(ctx context.Context, migration *model.EmailChannelMigration) error {
	if migration.AccountID == 0 {
		return errors.New("account_id is required")
	}
	if migration.InboxID == 0 {
		return errors.New("inbox_id is required")
	}
	if migration.TargetInboxID == 0 {
		return errors.New("target_inbox_id is required")
	}
	// Default status to pending if not set
	if migration.MigrationStatus == "" {
		migration.MigrationStatus = "pending"
	}
	if err := s.repo.Create(ctx, migration); err != nil {
		applogger.L().Errorf("EmailChannelMigrationService.Create error: %v", err)
		return err
	}
	return nil
}

// ListByAccount retrieves all email channel migrations for a given account.
func (s *EmailChannelMigrationService) ListByAccount(ctx context.Context, accountID uint) ([]model.EmailChannelMigration, error) {
	migrations, err := s.repo.FindByAccountID(ctx, accountID)
	if err != nil {
		applogger.L().Errorf("EmailChannelMigrationService.ListByAccount error: %v", err)
		return nil, err
	}
	return migrations, nil
}