use anyhow::Context as _;
use askama::Template;
use axum::{
    extract::{Path, State},
    response::{Html, IntoResponse as _, Redirect, Response},
};
use axum_extra::extract::Form;
use serde::Deserialize;
use sqlx::{query, query_scalar};
use uuid::Uuid;

use crate::{
    app_error::AppError,
    app_state::AppDbConn,
    base_pooler::BasePooler,
    base_user_perms::sync_perms_for_base,
    bases::Base,
    db_conns::{escape_identifier, init_role},
    settings::Settings,
    users::CurrentUser,
};

pub async fn list_bases_page(
    State(settings): State<Settings>,
    AppDbConn(mut app_db): AppDbConn,
    CurrentUser(current_user): CurrentUser,
) -> Result<Response, AppError> {
    let bases =
        Base::fetch_by_perm_any(current_user.id, vec!["configure", "connect"], &mut *app_db)
            .await?;
    #[derive(Template)]
    #[template(path = "list_bases.html")]
    struct ResponseTemplate {
        bases: Vec<Base>,
        settings: Settings,
    }
    Ok(Html(ResponseTemplate { bases, settings }.render()?).into_response())
}

pub async fn add_base_page(
    State(settings): State<Settings>,
    AppDbConn(mut app_db): AppDbConn,
    CurrentUser(current_user): CurrentUser,
) -> Result<Response, AppError> {
    // FIXME: CSRF
    let base = Base::insertable_builder()
        .url("".to_owned())
        .owner_id(current_user.id)
        .build()?
        .insert(&mut *app_db)
        .await?;
    query!(
        "
insert into base_user_perms
(id, base_id, user_id, perm)
values ($1, $2, $3, 'configure')",
        Uuid::now_v7(),
        base.id,
        current_user.id
    )
    .execute(&mut *app_db)
    .await?;
    Ok(Redirect::to(&format!("{}/d/{}/config", settings.root_path, base.id)).into_response())
}

#[derive(Deserialize)]
pub struct BaseConfigPagePath {
    base_id: Uuid,
}

pub async fn base_config_page_get(
    State(settings): State<Settings>,
    AppDbConn(mut app_db): AppDbConn,
    CurrentUser(current_user): CurrentUser,
    Path(params): Path<BaseConfigPagePath>,
) -> Result<Response, AppError> {
    // FIXME: auth
    let base = Base::fetch_by_id(params.base_id, &mut *app_db)
        .await?
        .ok_or(AppError::NotFound("no base found with that id".to_owned()))?;
    #[derive(Template)]
    #[template(path = "base_config.html")]
    struct ResponseTemplate {
        base: Base,
        settings: Settings,
    }
    Ok(Html(ResponseTemplate { base, settings }.render()?).into_response())
}

#[derive(Deserialize)]
pub struct BaseConfigPageForm {
    name: String,
    url: String,
}

pub async fn base_config_page_post(
    State(settings): State<Settings>,
    State(mut base_pooler): State<BasePooler>,
    AppDbConn(mut app_db): AppDbConn,
    CurrentUser(current_user): CurrentUser,
    Path(BaseConfigPagePath { base_id }): Path<BaseConfigPagePath>,
    Form(form): Form<BaseConfigPageForm>,
) -> Result<Response, AppError> {
    // FIXME: CSRF
    // FIXME: auth
    let base = Base::fetch_by_id(base_id, &mut *app_db)
        .await?
        .ok_or(AppError::NotFound("no base found with that id".to_owned()))?;
    query!(
        "update bases set name = $1, url = $2 where id = $3",
        &form.name,
        &form.url,
        &base_id
    )
    .execute(&mut *app_db)
    .await?;
    if form.url != base.url {
        base_pooler.close_for(base_id).await?;
        let mut client = base_pooler.acquire_for(base.id).await?;
        let rolname = format!("{}{}", base.user_role_prefix, current_user.id.simple());
        // Bootstrap user role with database connect privilege. If the user was
        // able to successfully authenticate a connection string, it should be
        // safe to say that they should be allowed to connect as an Interim
        // user.
        init_role(&rolname, &mut client).await?;
        let db_name: String = query_scalar!("select current_database()")
            .fetch_one(&mut *client)
            .await?
            .context("unable to select current_database()")?;
        query!("reset role").execute(&mut *client).await?;
        query(&format!(
            "grant connect on database {} to {}",
            escape_identifier(&db_name),
            escape_identifier(&rolname)
        ))
        .execute(&mut *client)
        .await?;
        sync_perms_for_base(base.id, &mut app_db, &mut client).await?;
    }
    Ok(Redirect::to(&format!("{}/d/{}/config", settings.root_path, base_id)).into_response())
}