use anyhow::Context as _;
use askama::Template;
use axum::{
    extract::{Path, State},
    response::{Html, IntoResponse, Redirect},
    routing::{get, post},
    Router,
};
use axum_extra::extract::Form;
use diesel::prelude::*;
use serde::Deserialize;
use uuid::Uuid;

use crate::{
    api_keys::ApiKey,
    app_error::AppError,
    app_state::{AppState, DbConn},
    csrf::generate_csrf_token,
    guards,
    nav::{BreadcrumbTrail, Navbar, NavbarBuilder, NAVBAR_ITEM_TEAMS},
    projects::{Project, DEFAULT_PROJECT_NAME},
    schema::{api_keys, team_memberships, teams},
    settings::Settings,
    team_memberships::TeamMembership,
    teams::Team,
    users::CurrentUser,
};

pub fn new_router() -> Router<AppState> {
    Router::new()
        .route("/teams", get(teams_page))
        .route("/teams/{team_id}", get(team_page))
        .route("/teams/{team_id}/new-api-key", post(post_new_api_key))
        .route("/teams/{team_id}/remove-api-key", post(remove_api_key))
        .route("/new-team", get(new_team_page))
        .route("/new-team", post(post_new_team))
}

async fn teams_page(
    State(Settings { base_path, .. }): State<Settings>,
    State(navbar_template): State<NavbarBuilder>,
    DbConn(conn): DbConn,
    CurrentUser(current_user): CurrentUser,
) -> Result<impl IntoResponse, AppError> {
    let teams: Vec<Team> = {
        let current_user = current_user.clone();
        conn.interact(move |conn| current_user.team_memberships().load(conn))
            .await
            .unwrap()
            .context("failed to load team memberships")
            .map(|memberships| memberships.into_iter().map(|(_, team)| team).collect())?
    };
    #[derive(Template)]
    #[template(path = "teams.html")]
    struct ResponseTemplate {
        base_path: String,
        breadcrumbs: BreadcrumbTrail,
        navbar: Navbar,
        teams: Vec<Team>,
    }
    Ok(Html(
        ResponseTemplate {
            breadcrumbs: BreadcrumbTrail::from_base_path(&base_path)
                .with_i18n_slug("en")
                .push_slug("Teams", "teams"),
            base_path,
            navbar: navbar_template.with_active_item(NAVBAR_ITEM_TEAMS).build(),
            teams,
        }
        .render()?,
    ))
}

async fn team_page(
    State(Settings { base_path, .. }): State<Settings>,
    Path(team_id): Path<Uuid>,
) -> impl IntoResponse {
    Redirect::to(&format!("{}/en/teams/{}/projects", base_path, team_id))
}

#[derive(Deserialize)]
struct PostNewApiKeyForm {
    csrf_token: String,
}

async fn post_new_api_key(
    State(Settings { base_path, .. }): State<Settings>,
    DbConn(db_conn): DbConn,
    Path(team_id): Path<Uuid>,
    CurrentUser(current_user): CurrentUser,
    Form(form): Form<PostNewApiKeyForm>,
) -> Result<impl IntoResponse, AppError> {
    guards::require_valid_csrf_token(&form.csrf_token, &current_user, &db_conn).await?;
    let team = guards::require_team_membership(&current_user, &team_id, &db_conn).await?;

    ApiKey::generate_for_team(&db_conn, team.id).await?;
    Ok(Redirect::to(&format!(
        "{}/en/teams/{}/projects",
        base_path,
        team.id.simple()
    ))
    .into_response())
}

#[derive(Deserialize)]
struct RemoveApiKeyForm {
    csrf_token: String,
    key_id: Uuid,
}

async fn remove_api_key(
    State(Settings { base_path, .. }): State<Settings>,
    DbConn(db_conn): DbConn,
    Path(team_id): Path<Uuid>,
    CurrentUser(current_user): CurrentUser,
    Form(form): Form<RemoveApiKeyForm>,
) -> Result<impl IntoResponse, AppError> {
    guards::require_valid_csrf_token(&form.csrf_token, &current_user, &db_conn).await?;
    let team = guards::require_team_membership(&current_user, &team_id, &db_conn).await?;

    let n_deleted = {
        let team_id = team.id;
        db_conn
            .interact::<_, Result<usize, AppError>>(move |conn| {
                diesel::delete(
                    api_keys::table
                        .filter(ApiKey::with_team(&team_id))
                        .filter(ApiKey::with_id(&form.key_id)),
                )
                .execute(conn)
                .context("failed to delete API key from database")
                .map_err(Into::into)
            })
            .await
            .unwrap()?
    };
    assert!(
        n_deleted < 2,
        "there should never be more than 1 API key with the same ID"
    );
    if n_deleted == 0 {
        Err(AppError::NotFoundError(
            "no API key with that ID and team found".to_owned(),
        ))
    } else {
        Ok(Redirect::to(&format!(
            "{}/en/teams/{}/projects",
            base_path,
            team.id.simple()
        ))
        .into_response())
    }
}

async fn new_team_page(
    State(Settings { base_path, .. }): State<Settings>,
    State(navbar_template): State<NavbarBuilder>,
    DbConn(db_conn): DbConn,
    CurrentUser(current_user): CurrentUser,
) -> Result<impl IntoResponse, AppError> {
    let csrf_token = generate_csrf_token(&db_conn, Some(current_user.id)).await?;

    #[derive(Template)]
    #[template(path = "new-team.html")]
    struct ResponseTemplate {
        base_path: String,
        breadcrumbs: BreadcrumbTrail,
        csrf_token: String,
        navbar: Navbar,
    }
    Ok(Html(
        ResponseTemplate {
            breadcrumbs: BreadcrumbTrail::from_base_path(&base_path)
                .with_i18n_slug("en")
                .push_slug("New Team", "new-team"),
            base_path,
            csrf_token,
            navbar: navbar_template.with_active_item(NAVBAR_ITEM_TEAMS).build(),
        }
        .render()?,
    ))
}

#[derive(Deserialize)]
struct PostNewTeamForm {
    name: String,
    csrf_token: String,
}

async fn post_new_team(
    DbConn(db_conn): DbConn,
    State(Settings { base_path, .. }): State<Settings>,
    CurrentUser(current_user): CurrentUser,
    Form(form): Form<PostNewTeamForm>,
) -> Result<impl IntoResponse, AppError> {
    guards::require_valid_csrf_token(&form.csrf_token, &current_user, &db_conn).await?;

    let team_id = Uuid::now_v7();
    let team = Team {
        id: team_id,
        name: form.name,
    };
    let team_membership = TeamMembership {
        team_id,
        user_id: current_user.id,
    };
    db_conn
        .interact::<_, Result<(), AppError>>(move |conn| {
            conn.transaction::<(), AppError, _>(move |conn| {
                diesel::insert_into(teams::table)
                    .values(&team)
                    .execute(conn)?;
                diesel::insert_into(team_memberships::table)
                    .values(&team_membership)
                    .execute(conn)?;
                Project::insert_new(conn, &team.id, DEFAULT_PROJECT_NAME)?;
                Ok(())
            })
        })
        .await
        .unwrap()
        .unwrap();
    ApiKey::generate_for_team(&db_conn, team_id).await?;
    Ok(Redirect::to(&format!("{}/en/teams/{}/projects", base_path, team_id)).into_response())
}