module main

struct Star {
	id      int @[primary; sql: serial]
	user_id int @[unique: 'repo_star']
	repo_id int @[unique: 'repo_star']
}

fn (mut app App) add_star(repo_id int, user_id int) ! {
	star := Star{
		repo_id: repo_id
		user_id: user_id
	}

	sql app.db {
		insert star into Star
	}!
}

fn (mut app App) find_user_starred_repos(user_id int) []Repo {
	stars := sql app.db {
		select from Star where user_id == user_id
	} or { [] }
	mut repos := []Repo{}

	for star in stars {
		repo := app.find_repo_by_id(star.repo_id) or { continue }

		repos << repo
	}

	return repos
}

fn (mut app App) toggle_repo_star(repo_id int, user_id int) ! {
	is_starred := app.check_repo_starred(repo_id, user_id)

	if is_starred {
		app.remove_star(repo_id, user_id)!
		app.decrement_repo_stars(repo_id)!
	} else {
		app.add_star(repo_id, user_id)!
		app.increment_repo_stars(repo_id)!
	}
}

fn (mut app App) check_repo_starred(repo_id int, user_id int) bool {
	stars := sql app.db {
		select from Star where repo_id == repo_id && user_id == user_id limit 1
	} or { [] }

	return stars.len != 0
}

fn (mut app App) remove_star(repo_id int, user_id int) ! {
	sql app.db {
		delete from Star where repo_id == repo_id && user_id == user_id
	}!
}