use std::str::FromStr;

use actix_web::{get, post, web, HttpResponse, Scope};
use actix_web_httpauth::extractors::bearer::BearerAuth;

use crate::activitypub::{
    builders::{
        move_person::prepare_move_person,
        undo_follow::prepare_undo_follow,
    },
};
use crate::config::Config;
use crate::database::{get_database_client, DatabaseError, DbPool};
use crate::errors::{HttpError, ValidationError};
use crate::mastodon_api::{
    accounts::types::Account,
    oauth::auth::get_current_user,
};
use crate::models::{
    profiles::helpers::find_aliases,
    profiles::queries::{get_profile_by_acct, get_profile_by_remote_actor_id},
    relationships::queries::{follow, unfollow},
    users::queries::set_user_password,
};
use crate::utils::passwords::hash_password;
use crate::webfinger::types::ActorAddress;
use super::helpers::{export_followers, export_follows};
use super::types::{MoveFollowersRequest, PasswordChangeRequest};

#[post("/change_password")]
async fn change_password_view(
    auth: BearerAuth,
    config: web::Data<Config>,
    db_pool: web::Data<DbPool>,
    request_data: web::Json<PasswordChangeRequest>,
) -> Result<HttpResponse, HttpError> {
    let db_client = &**get_database_client(&db_pool).await?;
    let current_user = get_current_user(db_client, auth.token()).await?;
    let password_hash = hash_password(&request_data.new_password)
        .map_err(|_| HttpError::InternalError)?;
    set_user_password(db_client, &current_user.id, password_hash).await?;
    let account = Account::from_user(current_user, &config.instance_url());
    Ok(HttpResponse::Ok().json(account))
}

#[get("/export_followers")]
async fn export_followers_view(
    auth: BearerAuth,
    config: web::Data<Config>,
    db_pool: web::Data<DbPool>,
) -> Result<HttpResponse, HttpError> {
    let db_client = &**get_database_client(&db_pool).await?;
    let current_user = get_current_user(db_client, auth.token()).await?;
    let csv = export_followers(
        db_client,
        &config.instance().hostname(),
        &current_user.id,
    ).await?;
    let response = HttpResponse::Ok()
        .content_type("text/csv")
        .body(csv);
    Ok(response)
}

#[get("/export_follows")]
async fn export_follows_view(
    auth: BearerAuth,
    config: web::Data<Config>,
    db_pool: web::Data<DbPool>,
) -> Result<HttpResponse, HttpError> {
    let db_client = &**get_database_client(&db_pool).await?;
    let current_user = get_current_user(db_client, auth.token()).await?;
    let csv = export_follows(
        db_client,
        &config.instance().hostname(),
        &current_user.id,
    ).await?;
    let response = HttpResponse::Ok()
        .content_type("text/csv")
        .body(csv);
    Ok(response)
}

#[post("/move_followers")]
async fn move_followers(
    auth: BearerAuth,
    config: web::Data<Config>,
    db_pool: web::Data<DbPool>,
    request_data: web::Json<MoveFollowersRequest>,
) -> Result<HttpResponse, HttpError> {
    let db_client = &mut **get_database_client(&db_pool).await?;
    let current_user = get_current_user(db_client, auth.token()).await?;
    let instance = config.instance();
    if request_data.from_actor_id.starts_with(&instance.url()) {
        return Err(ValidationError("can't move from local actor").into());
    };
    // Existence of actor is not verified because
    // the old profile could have been deleted
    let maybe_from_profile = match get_profile_by_remote_actor_id(
        db_client,
        &request_data.from_actor_id,
    ).await {
        Ok(profile) => Some(profile),
        Err(DatabaseError::NotFound(_)) => None,
        Err(other_error) => return Err(other_error.into()),
    };
    if maybe_from_profile.is_some() {
        // Find known aliases of the current user
        let mut aliases = find_aliases(db_client, &current_user.profile).await?
            .into_iter()
            .map(|profile| profile.actor_id(&instance.url()));
        if !aliases.any(|actor_id| actor_id == request_data.from_actor_id) {
            return Err(ValidationError("old profile is not an alias").into());
        };
    };
    let mut followers = vec![];
    for follower_address in request_data.followers_csv.lines() {
        let follower_acct = ActorAddress::from_str(follower_address)?
            .acct(&instance.hostname());
        // TODO: fetch unknown profiles
        let follower = get_profile_by_acct(db_client, &follower_acct).await?;
        if let Some(remote_actor) = follower.actor_json {
            // Add remote actor to activity recipients list
            followers.push(remote_actor);
        } else {
            // Immediately move local followers (only if alias can be verified)
            if let Some(ref from_profile) = maybe_from_profile {
                match unfollow(db_client, &follower.id, &from_profile.id).await {
                    Ok(maybe_follow_request_id) => {
                        // Send Undo(Follow) to a remote actor
                        let remote_actor = from_profile.actor_json.as_ref()
                            .expect("actor data must be present");
                        let follow_request_id = maybe_follow_request_id
                            .expect("follow request must exist");
                        prepare_undo_follow(
                            &instance,
                            &current_user,
                            remote_actor,
                            &follow_request_id,
                        ).enqueue(db_client).await?;
                    },
                    // Not a follower, ignore
                    Err(DatabaseError::NotFound(_)) => continue,
                    Err(other_error) => return Err(other_error.into()),
                };
                match follow(db_client, &follower.id, &current_user.id).await {
                    Ok(_) => (),
                    // Ignore if already following
                    Err(DatabaseError::AlreadyExists(_)) => (),
                    Err(other_error) => return Err(other_error.into()),
                };
            };
        };
    };
    prepare_move_person(
        &instance,
        &current_user,
        &request_data.from_actor_id,
        followers,
        None,
    ).enqueue(db_client).await?;

    let account = Account::from_user(current_user, &instance.url());
    Ok(HttpResponse::Ok().json(account))
}

pub fn settings_api_scope() -> Scope {
    web::scope("/api/v1/settings")
        .service(change_password_view)
        .service(export_followers_view)
        .service(export_follows_view)
        .service(move_followers)
}