package workers

import (
	"fmt"

	"gorm.io/gorm"

	db "git.zervo.org/scheduletogether/backend/internal/database"
)

func workerFriends_PurgeAbandonedRequests() {
	reporter := NewReporter("Friends", "PurgeAbandonedRequests")

	// Start a transaction
	tx := db.Db.Begin()

	// Get all friend requests
	reporter.Status("1/2: Get all friend requests")
	var friendRequests []db.FriendRequest
	err := tx.Model(&db.FriendRequest{}).Find(&friendRequests).Error
	if err != nil {
		tx.Rollback()
		reporter.Fail("Failed to retrieve friend requests from the database: " + err.Error())
		return
	}
	reporter.Status(fmt.Sprintf("Found %d pending requests", len(friendRequests)))

	// Loop over friend requests
	reporter.Status("2/2: Purge abandoned friend requests")
	var purged int
	for _, request := range friendRequests {
		// Get source user
		var sourceUser db.User
		err = tx.Where("uuid = ?", request.Source).First(&sourceUser).Error

		// If error, assume user doesn't exist anymore
		if err != nil {
			reporter.Status("Deleting abandoned friend request with source user " + request.Source)
			purged += 1
			err := tx.Model(&db.FriendRequest{}).Delete(&request).Error
			if err != nil {
				tx.Rollback()
				reporter.Fail("Failed to delete friend request from the database: " + err.Error())
				return
			}
			continue
		}
		reporter.Status(fmt.Sprintf("Purged %d abandoned requests", purged))

		// Get target user
		var targetUser db.User
		err = tx.Where("uuid = ?", request.Source).First(&targetUser).Error

		// If error, assume user doesn't exist anymore
		if err != nil {
			if err == gorm.ErrRecordNotFound {
				reporter.Status("Deleting abandoned friend request with target user " + request.Target)
				err := tx.Model(&db.FriendRequest{}).Delete(&request).Error
				if err != nil {
					tx.Rollback()
					reporter.Fail("Failed to delete friend request from the database: " + err.Error())
					return
				}
				continue
			}
		}
	}

	// Commit the transaction if everything is successful
	err = tx.Commit().Error
	if err != nil {
		tx.Rollback()
		reporter.Fail("Failed to commit transaction: " + err.Error())
		return
	}

	// Finish job
	reporter.Finish()
}