module main

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

fn (mut app App) watch_repo(repo_id int, user_id int) ! {
    watch := Watch{
        repo_id: repo_id
        user_id: user_id
    }

    sql app.db {
        insert watch into Watch
    }!
}

fn (mut app App) get_count_repo_watchers(repo_id int) int {
    return sql app.db {
        select count from Watch where repo_id == repo_id
    } or { 0 }
}

fn (mut app App) find_watching_repo_ids(user_id int) []int {
    watch_list := sql app.db {
        select from Watch where user_id == user_id
    } or { [] }

    return watch_list.map(it.repo_id)
}

fn (mut app App) toggle_repo_watcher_status(repo_id int, user_id int) ! {
    is_watching := app.check_repo_watcher_status(repo_id, user_id)

    if is_watching {
        app.unwatch_repo(repo_id, user_id)!
    } else {
        app.watch_repo(repo_id, user_id)!
    }
}

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

    return watches.len != 0
}

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