use anyhow::anyhow;
use askama_axum::Template;
use axum::{
    extract::{Path, State},
    http::status::StatusCode,
    response::{Html, IntoResponse, Redirect},
    routing::{get, post},
    Form, Router,
};
use diesel::{dsl::insert_into, prelude::*, result::Error::NotFound};
use serde::Deserialize;
use tower::ServiceBuilder;
use tower_http::{
    compression::CompressionLayer,
    services::{ServeDir, ServeFile},
    trace::TraceLayer,
};
use uuid::Uuid;

use crate::{
    api_keys::ApiKey,
    app_error::AppError,
    app_state::AppState,
    auth::{self, AuthInfo},
    csrf::{generate_csrf_token_for_user, validate_csrf_token_for_user},
    models::{Team, TeamMembership},
    projects::Project,
    schema,
    users::{CurrentUser, User},
};

pub fn new_router(state: AppState) -> Router<()> {
    let base_path = state.settings.base_path.clone();
    Router::new().nest(
        format!("{}", base_path).as_str(),
        Router::new()
            .route("/", get(landing_page))
            .route("/teams", get(teams_page))
            .route("/teams/{team_id}", get(team_page))
            .route("/teams/{team_id}/projects", get(projects_page))
            .route("/teams/{team_id}/new-api-key", post(post_new_api_key))
            .route("/new-team", get(new_team_page))
            .route("/new-team", post(post_new_team))
            .nest("/auth", auth::new_router())
            .fallback_service(
                ServeDir::new("static").not_found_service(ServeFile::new("static/_404.html")),
            )
            .layer(
                ServiceBuilder::new()
                    .layer(TraceLayer::new_for_http())
                    .layer(CompressionLayer::new()),
            )
            .with_state(state),
    )
}

async fn landing_page(State(state): State<AppState>) -> impl IntoResponse {
    Redirect::to(&format!("{}/teams", state.settings.base_path))
}

async fn teams_page(
    State(state): State<AppState>,
    CurrentUser(current_user): CurrentUser,
) -> Result<impl IntoResponse, AppError> {
    let current_user_id = current_user.id.clone();
    let teams_of_current_user = state
        .db_pool
        .get()
        .await?
        .interact(move |conn| {
            schema::team_memberships::table
                .inner_join(schema::teams::table)
                .filter(schema::team_memberships::user_id.eq(current_user_id))
                .select(Team::as_select())
                .load(conn)
        })
        .await
        .unwrap()
        .unwrap();
    #[derive(Template)]
    #[template(path = "teams.html")]
    struct ResponseTemplate {
        base_path: String,
        teams: Vec<Team>,
        current_user: User,
    }
    Ok(Html(
        ResponseTemplate {
            current_user,
            base_path: state.settings.base_path,
            teams: teams_of_current_user,
        }
        .render()?,
    )
    .into_response())
}

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

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

async fn post_new_api_key(
    State(state): State<AppState>,
    Path(team_id): Path<Uuid>,
    user_info: AuthInfo,
    Form(form): Form<PostNewApiKeyForm>,
) -> Result<impl IntoResponse, AppError> {
    let current_uid = user_info.sub.clone();
    let current_user = state
        .db_pool
        .get()
        .await?
        .interact(move |conn| {
            schema::users::table
                .filter(schema::users::uid.eq(current_uid))
                .select(User::as_select())
                .first(conn)
        })
        .await
        .unwrap() // Bubble up panic from callback
        .map_err(|diesel_err| match diesel_err {
            NotFound => AppError::InternalServerError(anyhow!(
                "user not found in database for uid {}",
                user_info.sub
            )),
            _ => AppError::InternalServerError(diesel_err.into()),
        })?;
    if !validate_csrf_token_for_user(&state.db_pool, &form.csrf_token, Some(current_user.id))
        .await?
    {
        return Ok((StatusCode::FORBIDDEN, "invalid CSRF token".to_string()).into_response());
    }
    let team_membership = match state
        .db_pool
        .get()
        .await?
        .interact(move |conn| {
            schema::team_memberships::table
                .filter(schema::team_memberships::team_id.eq(team_id))
                .filter(schema::team_memberships::user_id.eq(current_user.id))
                .select(TeamMembership::as_select())
                .first(conn)
                .optional()
        })
        .await
        .unwrap()
        .unwrap()
    {
        Some(team_membership) => team_membership,
        None => {
            return Ok((
                StatusCode::FORBIDDEN,
                "not a member of requested team".to_string(),
            )
                .into_response());
        }
    };
    ApiKey::generate_for_team(&state.db_pool, team_membership.team_id.clone()).await?;
    Ok(Redirect::to(&format!(
        "{}/teams/{}/projects",
        state.settings.base_path,
        team_membership.team_id.hyphenated().to_string()
    ))
    .into_response())
}

async fn new_team_page(
    State(state): State<AppState>,
    CurrentUser(current_user): CurrentUser,
) -> Result<impl IntoResponse, AppError> {
    let csrf_token =
        generate_csrf_token_for_user(&state.db_pool, Some(current_user.id.clone())).await?;
    #[derive(Template)]
    #[template(path = "new-team.html")]
    struct ResponseTemplate {
        base_path: String,
        csrf_token: String,
        current_user: User,
    }
    Ok(Html(
        ResponseTemplate {
            csrf_token,
            current_user,
            base_path: state.settings.base_path,
        }
        .render()?,
    ))
}

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

async fn post_new_team(
    State(state): State<AppState>,
    user_info: AuthInfo,
    Form(form): Form<PostNewTeamForm>,
) -> Result<impl IntoResponse, AppError> {
    let current_uid = user_info.sub.clone();
    let current_user = state
        .db_pool
        .get()
        .await?
        .interact(move |conn| {
            schema::users::table
                .filter(schema::users::uid.eq(current_uid))
                .select(User::as_select())
                .first(conn)
        })
        .await
        .unwrap()
        .unwrap();
    if !validate_csrf_token_for_user(
        &state.db_pool,
        &form.csrf_token,
        Some(current_user.id.clone()),
    )
    .await?
    {
        return Err(anyhow!("Invalid CSRF token").into());
    }
    let team_id = Uuid::now_v7();
    let team = Team {
        id: team_id.clone(),
        name: form.name,
    };
    let team_membership = TeamMembership {
        team_id: team_id.clone(),
        user_id: current_user.id,
        roles: vec![Some("OWNER".to_string())],
    };
    state
        .db_pool
        .get()
        .await?
        .interact(move |conn| {
            conn.transaction(move |conn| {
                insert_into(schema::teams::table)
                    .values(team)
                    .execute(conn)?;
                insert_into(schema::team_memberships::table)
                    .values(team_membership)
                    .execute(conn)?;
                diesel::QueryResult::Ok(())
            })
        })
        .await
        .unwrap()
        .unwrap();
    ApiKey::generate_for_team(&state.db_pool, team_id.clone()).await?;
    Ok(Redirect::to(&format!(
        "{}/teams/{}/projects",
        state.settings.base_path, team_id
    )))
}

async fn projects_page(
    State(state): State<AppState>,
    Path(team_id): Path<Uuid>,
    CurrentUser(current_user): CurrentUser,
) -> Result<impl IntoResponse, AppError> {
    let current_user_id = current_user.id.clone();
    let team = match state
        .db_pool
        .get()
        .await?
        .interact(move |conn| {
            schema::team_memberships::table
                .inner_join(schema::teams::table)
                .filter(schema::team_memberships::user_id.eq(current_user_id))
                .filter(schema::teams::id.eq(team_id))
                .select(Team::as_select())
                .first(conn)
                .optional()
        })
        .await
        .unwrap()
        .unwrap()
    {
        Some(team) => team,
        None => {
            return Ok((
                StatusCode::FORBIDDEN,
                "not a member of requested team".to_string(),
            )
                .into_response());
        }
    };
    let team_id = team.id.clone();
    let api_keys = state
        .db_pool
        .get()
        .await?
        .interact(move |conn| {
            schema::api_keys::table
                .filter(schema::api_keys::team_id.eq(team_id))
                .select(ApiKey::as_select())
                .load(conn)
        })
        .await
        .unwrap()
        .unwrap();
    #[derive(Template)]
    #[template(path = "projects.html")]
    struct ResponseTemplate {
        base_path: String,
        csrf_token: String,
        keys: Vec<ApiKey>,
        projects: Vec<Project>,
        team: Team,
        current_user: User,
    }
    let csrf_token =
        generate_csrf_token_for_user(&state.db_pool, Some(current_user.id.clone())).await?;
    Ok(Html(
        ResponseTemplate {
            csrf_token,
            current_user,
            team,
            base_path: state.settings.base_path,
            keys: api_keys,
            projects: vec![],
        }
        .render()?,
    )
    .into_response())
}