use std::{collections::HashMap, net::SocketAddr};

use askama::Template;
use axum::{
    body::Body,
    debug_handler,
    extract::{ConnectInfo, Extension, Host, Path, Query, Request, State},
    http::{HeaderMap, StatusCode},
    response::{IntoResponse, Redirect, Response, Result},
    Form,
};
use axum_extra::extract::cookie::{Cookie, CookieJar};
use chrono::Duration;
use serde::Deserialize;
use tracing::{event, Level};

use crate::{config::Config, consts, data::db, email, model, utils, AppState};

pub mod ron;

impl axum::response::IntoResponse for db::DBError {
    fn into_response(self) -> Response {
        let body = MessageTemplate {
            user: None,
            message: &self.to_string(),
        };
        (StatusCode::INTERNAL_SERVER_ERROR, body).into_response()
    }
}

///// HOME /////

#[derive(Template)]
#[template(path = "home.html")]
struct HomeTemplate {
    user: Option<model::User>,
    recipes: Vec<(i64, String)>,
    current_recipe_id: Option<i64>,
}

#[debug_handler]
pub async fn home_page(
    State(connection): State<db::Connection>,
    Extension(user): Extension<Option<model::User>>,
) -> Result<impl IntoResponse> {
    let recipes = connection.get_all_recipe_titles().await?;

    Ok(HomeTemplate {
        user,
        current_recipe_id: None,
        recipes,
    })
}

///// VIEW RECIPE /////

#[derive(Template)]
#[template(path = "view_recipe.html")]
struct ViewRecipeTemplate {
    user: Option<model::User>,
    recipes: Vec<(i64, String)>,
    current_recipe_id: Option<i64>,
    current_recipe: model::Recipe,
}

#[debug_handler]
pub async fn view_recipe(
    State(connection): State<db::Connection>,
    Extension(user): Extension<Option<model::User>>,
    Path(recipe_id): Path<i64>,
) -> Result<Response> {
    let recipes = connection.get_all_recipe_titles().await?;
    match connection.get_recipe(recipe_id).await? {
        Some(recipe) => Ok(ViewRecipeTemplate {
            user,
            current_recipe_id: Some(recipe.id),
            recipes,
            current_recipe: recipe,
        }
        .into_response()),
        None => Ok(MessageTemplate {
            user,
            message: &format!("Cannot find the recipe {}", recipe_id),
        }
        .into_response()),
    }
}

///// EDIT/NEW RECIPE /////

// #[derive(Template)]
// #[template(path = "edit_recipe.html")]
// struct EditRecipeTemplate {
//     user: Option<model::User>,
//     recipes: Vec<(i64, String)>,
//     current_recipe_id: Option<i64>,

//     current_recipe: model::Recipe,
// }

// #[get("/recipe/edit/{id}")]
// pub async fn edit_recipe(
//     req: HttpRequest,
//     path: web::Path<(i64,)>,
//     connection: web::Data<db::Connection>,
// ) -> Result<HttpResponse> {
//     let (id,) = path.into_inner();
//     let user = match get_current_user(&req, connection.clone()).await {
//         Some(u) => u,
//         None => {
//             return Ok(MessageTemplate {
//                 user: None,
//                 message: "Cannot edit a recipe without being logged in",
//             }
//             .to_response())
//         }
//     };

//     let recipe = connection.get_recipe_async(id).await?;

//     if recipe.user_id != user.id {
//         return Ok(MessageTemplate {
//             message: "Cannot edit a recipe you don't own",
//             user: Some(user),
//         }
//         .to_response());
//     }

//     let recipes = connection.get_all_recipe_titles_async().await?;

//     Ok(EditRecipeTemplate {
//         user: Some(user),
//         current_recipe_id: Some(recipe.id),
//         recipes,
//         current_recipe: recipe,
//     }
//     .to_response())
// }

// #[get("/recipe/new")]
// pub async fn new_recipe(
//     req: HttpRequest,
//     connection: web::Data<db::Connection>,
// ) -> Result<HttpResponse> {
//     let user = match get_current_user(&req, connection.clone()).await {
//         Some(u) => u,
//         None => {
//             return Ok(MessageTemplate {
//                 message: "Cannot create a recipe without being logged in",
//                 user: None,
//             }
//             .to_response())
//         }
//     };

//     let recipe_id = connection.create_recipe_async(user.id).await?;
//     let recipes = connection.get_all_recipe_titles_async().await?;
//     let user_id = user.id;

//     Ok(EditRecipeTemplate {
//         user: Some(user),
//         current_recipe_id: Some(recipe_id),
//         recipes,
//         current_recipe: model::Recipe::empty(recipe_id, user_id),
//     }
//     .to_response())
// }

///// MESSAGE /////

#[derive(Template)]
#[template(path = "message_without_user.html")]
struct MessageWithoutUser<'a> {
    message: &'a str,
}

#[derive(Template)]
#[template(path = "message.html")]
struct MessageTemplate<'a> {
    user: Option<model::User>,
    message: &'a str,
}

//// SIGN UP /////

#[derive(Template)]
#[template(path = "sign_up_form.html")]
struct SignUpFormTemplate {
    user: Option<model::User>,
    email: String,
    message: String,
    message_email: String,
    message_password: String,
}

#[debug_handler]
pub async fn sign_up_get(
    Extension(user): Extension<Option<model::User>>,
) -> Result<impl IntoResponse> {
    Ok(SignUpFormTemplate {
        user,
        email: String::new(),
        message: String::new(),
        message_email: String::new(),
        message_password: String::new(),
    })
}

#[derive(Deserialize, Debug)]
pub struct SignUpFormData {
    email: String,
    password_1: String,
    password_2: String,
}

enum SignUpError {
    InvalidEmail,
    PasswordsNotEqual,
    InvalidPassword,
    UserAlreadyExists,
    DatabaseError,
    UnableSendEmail,
}

#[debug_handler(state = AppState)]
pub async fn sign_up_post(
    Host(host): Host,
    State(connection): State<db::Connection>,
    State(config): State<Config>,
    Extension(user): Extension<Option<model::User>>,
    Form(form_data): Form<SignUpFormData>,
) -> Result<Response> {
    fn error_response(
        error: SignUpError,
        form_data: &SignUpFormData,
        user: Option<model::User>,
    ) -> Result<Response> {
        Ok(SignUpFormTemplate {
            user,
            email: form_data.email.clone(),
            message_email: match error {
                SignUpError::InvalidEmail => "Invalid email",
                _ => "",
            }
            .to_string(),
            message_password: match error {
                SignUpError::PasswordsNotEqual => "Passwords don't match",
                SignUpError::InvalidPassword => "Password must have at least eight characters",
                _ => "",
            }
            .to_string(),
            message: match error {
                SignUpError::UserAlreadyExists => "This email is not available",
                SignUpError::DatabaseError => "Database error",
                SignUpError::UnableSendEmail => "Unable to send the validation email",
                _ => "",
            }
            .to_string(),
        }
        .into_response())
    }

    // Validation of email and password.
    if let common::utils::EmailValidation::NotValid =
        common::utils::validate_email(&form_data.email)
    {
        return error_response(SignUpError::InvalidEmail, &form_data, user);
    }

    if form_data.password_1 != form_data.password_2 {
        return error_response(SignUpError::PasswordsNotEqual, &form_data, user);
    }

    if let common::utils::PasswordValidation::TooShort =
        common::utils::validate_password(&form_data.password_1)
    {
        return error_response(SignUpError::InvalidPassword, &form_data, user);
    }

    match connection
        .sign_up(&form_data.email, &form_data.password_1)
        .await
    {
        Ok(db::SignUpResult::UserAlreadyExists) => {
            error_response(SignUpError::UserAlreadyExists, &form_data, user)
        }
        Ok(db::SignUpResult::UserCreatedWaitingForValidation(token)) => {
            let url = utils::get_url_from_host(&host);

            let email = form_data.email.clone();
            match email::send_email(
                &email,
                &format!(
                    "Follow this link to confirm your inscription: {}/validation?validation_token={}",
                    url, token
                ),
                &config.smtp_relay_address,
                &config.smtp_login,
                &config.smtp_password,
            )
            .await
            {
                Ok(()) => Ok(MessageTemplate {
                    user,
                    message: "An email has been sent, follow the link to validate your account.",
                }
                .into_response()),
                Err(_) => {
                    // error!("Email validation error: {}", error); // TODO: log
                    error_response(SignUpError::UnableSendEmail, &form_data, user)
                }
            }
        }
        Err(_) => {
            // error!("Signup database error: {}", error);
            error_response(SignUpError::DatabaseError, &form_data, user)
        }
    }
}

#[debug_handler]
pub async fn sign_up_validation(
    State(connection): State<db::Connection>,
    Extension(user): Extension<Option<model::User>>,
    ConnectInfo(addr): ConnectInfo<SocketAddr>,
    Query(query): Query<HashMap<String, String>>,
    headers: HeaderMap,
) -> Result<(CookieJar, impl IntoResponse)> {
    let mut jar = CookieJar::from_headers(&headers);
    if user.is_some() {
        return Ok((
            jar,
            MessageTemplate {
                user,
                message: "User already exists",
            },
        ));
    }
    let (client_ip, client_user_agent) = utils::get_ip_and_user_agent(&headers, addr);
    match query.get("validation_token") {
        // 'validation_token' exists only when a user tries to validate a new account.
        Some(token) => {
            match connection
                .validation(
                    token,
                    Duration::seconds(consts::VALIDATION_TOKEN_DURATION),
                    &client_ip,
                    &client_user_agent,
                )
                .await?
            {
                db::ValidationResult::Ok(token, user_id) => {
                    let cookie = Cookie::new(consts::COOKIE_AUTH_TOKEN_NAME, token);
                    jar = jar.add(cookie);
                    let user = connection.load_user(user_id).await?;
                    Ok((
                        jar,
                        MessageTemplate {
                            user,
                            message: "Email validation successful, your account has been created",
                        },
                    ))
                }
                db::ValidationResult::ValidationExpired => Ok((
                    jar,
                    MessageTemplate {
                        user,
                        message: "The validation has expired. Try to sign up again",
                    },
                )),
                db::ValidationResult::UnknownUser => Ok((
                    jar,
                    MessageTemplate {
                        user,
                        message: "Validation error. Try to sign up again",
                    },
                )),
            }
        }
        None => Ok((
            jar,
            MessageTemplate {
                user,
                message: "Validation error",
            },
        )),
    }
}

///// SIGN IN /////

#[derive(Template)]
#[template(path = "sign_in_form.html")]
struct SignInFormTemplate {
    user: Option<model::User>,
    email: String,
    message: String,
}

#[debug_handler]
pub async fn sign_in_get(
    Extension(user): Extension<Option<model::User>>,
) -> Result<impl IntoResponse> {
    Ok(SignInFormTemplate {
        user,
        email: String::new(),
        message: String::new(),
    })
}

#[derive(Deserialize, Debug)]
pub struct SignInFormData {
    email: String,
    password: String,
}

#[debug_handler]
pub async fn sign_in_post(
    ConnectInfo(addr): ConnectInfo<SocketAddr>,
    State(connection): State<db::Connection>,
    Extension(user): Extension<Option<model::User>>,
    headers: HeaderMap,
    Form(form_data): Form<SignInFormData>,
) -> Result<(CookieJar, Response)> {
    let jar = CookieJar::from_headers(&headers);
    let (client_ip, client_user_agent) = utils::get_ip_and_user_agent(&headers, addr);

    match connection
        .sign_in(
            &form_data.email,
            &form_data.password,
            &client_ip,
            &client_user_agent,
        )
        .await?
    {
        db::SignInResult::AccountNotValidated => Ok((
            jar,
            SignInFormTemplate {
                user,
                email: form_data.email,
                message: "This account must be validated first".to_string(),
            }
            .into_response(),
        )),
        db::SignInResult::UserNotFound | db::SignInResult::WrongPassword => Ok((
            jar,
            SignInFormTemplate {
                user,
                email: form_data.email,
                message: "Wrong email or password".to_string(),
            }
            .into_response(),
        )),
        db::SignInResult::Ok(token, _user_id) => {
            let cookie = Cookie::new(consts::COOKIE_AUTH_TOKEN_NAME, token);
            Ok((jar.add(cookie), Redirect::to("/").into_response()))
        }
    }
}

///// SIGN OUT /////

#[debug_handler]
pub async fn sign_out(
    State(connection): State<db::Connection>,
    req: Request<Body>,
) -> Result<(CookieJar, Redirect)> {
    let mut jar = CookieJar::from_headers(req.headers());
    if let Some(token_cookie) = jar.get(consts::COOKIE_AUTH_TOKEN_NAME) {
        let token = token_cookie.value().to_string();
        jar = jar.remove(consts::COOKIE_AUTH_TOKEN_NAME);
        connection.sign_out(&token).await?;
    }
    Ok((jar, Redirect::to("/")))
}

///// RESET PASSWORD /////

#[derive(Template)]
#[template(path = "ask_reset_password.html")]
struct AskResetPasswordTemplate {
    user: Option<model::User>,
    email: String,
    message: String,
    message_email: String,
}

#[debug_handler]
pub async fn ask_reset_password_get(
    Extension(user): Extension<Option<model::User>>,
) -> Result<Response> {
    if user.is_some() {
        Ok(MessageTemplate {
            user,
            message: "Can't ask to reset password when already logged in",
        }
        .into_response())
    } else {
        Ok(AskResetPasswordTemplate {
            user,
            email: String::new(),
            message: String::new(),
            message_email: String::new(),
        }
        .into_response())
    }
}

#[derive(Deserialize, Debug)]
pub struct AskResetPasswordForm {
    email: String,
}

enum AskResetPasswordError {
    InvalidEmail,
    EmailAlreadyReset,
    EmailUnknown,
    UnableSendEmail,
    DatabaseError,
}

#[debug_handler(state = AppState)]
pub async fn ask_reset_password_post(
    Host(host): Host,
    State(connection): State<db::Connection>,
    State(config): State<Config>,
    Extension(user): Extension<Option<model::User>>,
    Form(form_data): Form<AskResetPasswordForm>,
) -> Result<Response> {
    fn error_response(
        error: AskResetPasswordError,
        email: &str,
        user: Option<model::User>,
    ) -> Result<Response> {
        Ok(AskResetPasswordTemplate {
            user,
            email: email.to_string(),
            message_email: match error {
                AskResetPasswordError::InvalidEmail => "Invalid email",
                _ => "",
            }
            .to_string(),
            message: match error {
                AskResetPasswordError::EmailAlreadyReset => {
                    "The password has already been reset for this email"
                }
                AskResetPasswordError::EmailUnknown => "Email unknown",
                AskResetPasswordError::UnableSendEmail => "Unable to send the reset password email",
                AskResetPasswordError::DatabaseError => "Database error",
                _ => "",
            }
            .to_string(),
        }
        .into_response())
    }

    // Validation of email.
    if let common::utils::EmailValidation::NotValid =
        common::utils::validate_email(&form_data.email)
    {
        return error_response(AskResetPasswordError::InvalidEmail, &form_data.email, user);
    }

    match connection
        .get_token_reset_password(
            &form_data.email,
            Duration::seconds(consts::VALIDATION_PASSWORD_RESET_TOKEN_DURATION),
        )
        .await
    {
        Ok(db::GetTokenResetPasswordResult::PasswordAlreadyReset) => error_response(
            AskResetPasswordError::EmailAlreadyReset,
            &form_data.email,
            user,
        ),
        Ok(db::GetTokenResetPasswordResult::EmailUnknown) => {
            error_response(AskResetPasswordError::EmailUnknown, &form_data.email, user)
        }
        Ok(db::GetTokenResetPasswordResult::Ok(token)) => {
            let url = utils::get_url_from_host(&host);
            match email::send_email(
                &form_data.email,
                &format!(
                    "Follow this link to reset your password: {}/reset_password?reset_token={}",
                    url, token
                ),
                &config.smtp_relay_address,
                &config.smtp_login,
                &config.smtp_password,
            )
            .await
            {
                Ok(()) => Ok(MessageTemplate {
                    user,
                    message: "An email has been sent, follow the link to reset your password.",
                }
                .into_response()),
                Err(_) => {
                    // error!("Email validation error: {}", error); // TODO: log
                    error_response(
                        AskResetPasswordError::UnableSendEmail,
                        &form_data.email,
                        user,
                    )
                }
            }
        }
        Err(error) => {
            event!(Level::ERROR, "{}", error);
            error_response(AskResetPasswordError::DatabaseError, &form_data.email, user)
        }
    }
}

#[derive(Template)]
#[template(path = "reset_password.html")]
struct ResetPasswordTemplate {
    user: Option<model::User>,
    reset_token: String,
    message: String,
    message_password: String,
}

#[debug_handler]
pub async fn reset_password_get(
    Extension(user): Extension<Option<model::User>>,
    Query(query): Query<HashMap<String, String>>,
) -> Result<Response> {
    if let Some(reset_token) = query.get("reset_token") {
        Ok(ResetPasswordTemplate {
            user,
            reset_token: reset_token.to_string(),
            message: String::new(),
            message_password: String::new(),
        }
        .into_response())
    } else {
        Ok(MessageTemplate {
            user,
            message: "Reset token missing",
        }
        .into_response())
    }
}

#[derive(Deserialize, Debug)]
pub struct ResetPasswordForm {
    password_1: String,
    password_2: String,
    reset_token: String,
}

enum ResetPasswordError {
    PasswordsNotEqual,
    InvalidPassword,
    TokenExpired,
    DatabaseError,
}

#[debug_handler]
pub async fn reset_password_post(
    State(connection): State<db::Connection>,
    Extension(user): Extension<Option<model::User>>,
    Form(form_data): Form<ResetPasswordForm>,
) -> Result<Response> {
    fn error_response(
        error: ResetPasswordError,
        form_data: &ResetPasswordForm,
        user: Option<model::User>,
    ) -> Result<Response> {
        Ok(ResetPasswordTemplate {
            user,
            reset_token: form_data.reset_token.clone(),
            message_password: match error {
                ResetPasswordError::PasswordsNotEqual => "Passwords don't match",
                ResetPasswordError::InvalidPassword => {
                    "Password must have at least eight characters"
                }
                _ => "",
            }
            .to_string(),
            message: match error {
                ResetPasswordError::TokenExpired => "Token expired, try to reset password again",
                ResetPasswordError::DatabaseError => "Database error",
                _ => "",
            }
            .to_string(),
        }
        .into_response())
    }

    if form_data.password_1 != form_data.password_2 {
        return error_response(ResetPasswordError::PasswordsNotEqual, &form_data, user);
    }

    if let common::utils::PasswordValidation::TooShort =
        common::utils::validate_password(&form_data.password_1)
    {
        return error_response(ResetPasswordError::InvalidPassword, &form_data, user);
    }

    match connection
        .reset_password(
            &form_data.password_1,
            &form_data.reset_token,
            Duration::seconds(consts::VALIDATION_PASSWORD_RESET_TOKEN_DURATION),
        )
        .await
    {
        Ok(db::ResetPasswordResult::Ok) => Ok(MessageTemplate {
            user,
            message: "Your password has been reset",
        }
        .into_response()),
        Ok(db::ResetPasswordResult::ResetTokenExpired) => {
            error_response(ResetPasswordError::TokenExpired, &form_data, user)
        }
        Err(_) => error_response(ResetPasswordError::DatabaseError, &form_data, user),
    }
}

///// EDIT PROFILE /////

#[derive(Template)]
#[template(path = "profile.html")]
struct ProfileTemplate {
    user: Option<model::User>,
}

#[debug_handler]
pub async fn edit_user(
    State(connection): State<db::Connection>,
    Extension(user): Extension<Option<model::User>>,
) -> Response {
    if user.is_some() {
        ProfileTemplate { user }.into_response()
    } else {
        MessageTemplate {
            user: None,
            message: "Not logged in",
        }
        .into_response()
    }
}

///// 404 /////
#[debug_handler]
pub async fn not_found() -> Result<impl IntoResponse> {
    Ok(MessageWithoutUser {
        message: "404: Not found",
    })
}