use std::sync::mpsc::Sender;

use crate::{
    db::{insert_new_user, DbPool, NewUserEntity, UserEntity},
    models::ApiResponse,
    requests::AppState,
    services::{auth_token::generate_new_user_token, hash_string, UserConfirmationMessage},
};
use axum::{
    debug_handler,
    extract::State,
    response::{IntoResponse, Response},
    Json,
};
use http::StatusCode;
use pasetors::{keys::SymmetricKey, version4::V4};
use tracing::debug;

use super::models::{UserRegistrationRequest, UserRegistrationResponse};

#[debug_handler]
pub async fn user_registration_post_handler(
    State(state): State<AppState>,
    Json(request): Json<UserRegistrationRequest>,
) -> Result<Response, Response> {
    let env = state.env();

    register_new_user_request(
        request,
        state.pool(),
        env.token_key(),
        env.send_verification_email(),
        env.email_sender(),
    )
    .await
}

async fn register_new_user_request(
    body: UserRegistrationRequest,
    pool: &DbPool,
    signing_key: &SymmetricKey<V4>,
    send_verification_email: bool,
    email_sender: &Sender<UserConfirmationMessage>,
) -> Result<Response, Response> {
    debug!(?body, send_verification_email);

    let UserRegistrationRequest {
        username,
        password,
        email,
        name,
    } = body;

    let hashed_password = hash_string(password);

    let new_user = NewUserEntity {
        username,
        password: hashed_password.to_string(),
        email,
        name,
    };

    let UserEntity { id: user_id, name, email , ..} = insert_new_user(pool, new_user).await
    	.map_err(|err| {
    		if err.is_duplicate_record() {
    			(StatusCode::CONFLICT, ApiResponse::error("There is already an account associated with this username or email address.").into_json_response()).into_response()
    		} else {
    			(StatusCode::INTERNAL_SERVER_ERROR, ApiResponse::error("An error occurred while creating your new user account. Please try again later.").into_json_response()).into_response()
    		}
    	})?;

    let (auth_token, expiration) = generate_new_user_token(signing_key, user_id);

    let response_body = if send_verification_email {
        let new_user_confirmation_message = UserConfirmationMessage {
            email,
            name,
            auth_token: auth_token.clone(),
        };

        let _ = email_sender
            .send(new_user_confirmation_message)
            .inspect_err(|err| {
                eprintln!("Got the rollowing error while sending across the channel: {err}");
            });

        UserRegistrationResponse {
            id: user_id,
            expiration,
            auth_token: None,
        }
    } else {
        UserRegistrationResponse {
            id: user_id,
            expiration,
            auth_token: Some(auth_token),
        }
    };

    let response = (
        StatusCode::CREATED,
        ApiResponse::new(response_body).into_json_response(),
    );

    Ok(response.into_response())
}