use actix_web::{web, HttpResponse, Responder};
use rinja::Template;
use serde::Deserialize;
use sqlx::PgPool;

use crate::{
    endpoints::assignment::PlanEventPersonalTablePartialTemplate,
    models::{Assignment, Availabillity, Event, Function, Role, User},
    utils::{
        event_planning_template::{
            generate_availabillity_assignment_list, generate_status_whether_staff_is_required,
        },
        ApplicationError,
    },
};

#[derive(Deserialize)]
pub struct AssignmentQuery {
    availabillity: i32,
    function: u8,
    event: i32,
}

#[actix_web::post("/assignments/new")]
pub async fn post(
    user: web::ReqData<User>,
    pool: web::Data<PgPool>,
    query: web::Query<AssignmentQuery>,
) -> Result<impl Responder, ApplicationError> {
    let Some(event) = Event::read_by_id_including_location(pool.get_ref(), query.event).await?
    else {
        return Ok(HttpResponse::NotFound().finish());
    };

    let user_is_admin_or_area_manager_of_event_area = user.role == Role::Admin
        || (user.role == Role::AreaManager
            && user.area_id == event.location.as_ref().unwrap().area_id);

    if !user_is_admin_or_area_manager_of_event_area {
        return Err(ApplicationError::Unauthorized);
    }

    let Some(availability) =
        Availabillity::read_by_id_including_user(pool.get_ref(), query.availabillity).await?
    else {
        return Ok(HttpResponse::NotFound().finish());
    };

    let availability_user_not_in_event_location_area =
        availability.user.as_ref().unwrap().area_id != event.location.as_ref().unwrap().area_id;

    let existing_assignments_for_availabillity =
        Assignment::read_all_by_availabillity(pool.get_ref(), availability.id).await?;
    let has_start_time_during_event =
        |a: &Assignment| a.start_time >= event.start_time && a.start_time <= event.end_time;
    let has_end_time_during_event =
        |a: &Assignment| a.end_time >= event.start_time && a.end_time <= event.end_time;

    let availability_already_assigned = existing_assignments_for_availabillity
        .iter()
        .any(|a| has_start_time_during_event(a) || has_end_time_during_event(a));

    let function = Function::try_from(query.function)?;
    let user_not_qualified_for_assigned_function =
        availability.user.as_ref().unwrap().function < function;

    let a = Assignment::count_by_event_and_function(pool.get_ref(), event.id, function).await?;
    let event_already_has_enough_assignments_for_function = match function {
        Function::Posten => a >= event.amount_of_posten as i64,
        Function::Fuehrungsassistent => event.voluntary_fuehrungsassistent && a >= 1,
        Function::Wachhabender => event.voluntary_wachhabender && a >= 1,
    };

    if availability_user_not_in_event_location_area
        || availability_already_assigned
        || user_not_qualified_for_assigned_function
        || event_already_has_enough_assignments_for_function
    {
        // TODO: Fehlermeldung verbessern
        return Ok(HttpResponse::BadRequest().body(format!("{availability_user_not_in_event_location_area} {availability_already_assigned} {user_not_qualified_for_assigned_function} {event_already_has_enough_assignments_for_function}")));
    }

    Assignment::create(
        pool.get_ref(),
        event.id,
        availability.id,
        function,
        event.start_time,
        event.end_time,
    )
    .await?;

    let availabillities = generate_availabillity_assignment_list(pool.get_ref(), &event).await?;

    let (
        further_posten_required,
        further_fuehrungsassistent_required,
        further_wachhabender_required,
    ) = generate_status_whether_staff_is_required(pool.get_ref(), &event).await?;

    let template = PlanEventPersonalTablePartialTemplate {
        event,
        availabillities,
        further_posten_required,
        further_fuehrungsassistent_required,
        further_wachhabender_required,
    };

    Ok(HttpResponse::Ok().body(template.render()?))
}