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
    }!
}