use argon2::{
    Algorithm, Argon2, Params, PasswordHasher, Version,
    password_hash::{SaltString, rand_core::OsRng},
};
use linkify::LinkFinder;
use once_cell::sync::Lazy;
use sqlx::{Connection, Executor, PgConnection, PgPool};
use uuid::Uuid;
use wiremock::MockServer;
use zero2prod::{
    configuration::{DatabaseSettings, get_configuration},
    email_client::EmailClient,
    issue_delivery_worker::{ExecutionOutcome, try_execute_task},
    startup::Application,
    telemetry::init_subscriber,
};

static TRACING: Lazy<()> = Lazy::new(|| {
    if std::env::var("TEST_LOG").is_ok() {
        init_subscriber(std::io::stdout);
    } else {
        init_subscriber(std::io::sink);
    }
});

pub struct ConfirmationLinks {
    pub html: reqwest::Url,
    pub text: reqwest::Url,
}

pub struct TestUser {
    pub user_id: Uuid,
    pub username: String,
    pub password: String,
}

impl TestUser {
    pub fn generate() -> Self {
        Self {
            user_id: Uuid::new_v4(),
            username: Uuid::new_v4().to_string(),
            password: Uuid::new_v4().to_string(),
        }
    }

    pub async fn store(&self, connection_pool: &PgPool) {
        let salt = SaltString::generate(&mut OsRng);
        let password_hash = Argon2::new(
            Algorithm::Argon2id,
            Version::V0x13,
            Params::new(1500, 2, 1, None).unwrap(),
        )
        .hash_password(self.password.as_bytes(), &salt)
        .unwrap()
        .to_string();
        sqlx::query!(
            "INSERT INTO users (user_id, username, password_hash) VALUES ($1, $2, $3)",
            self.user_id,
            self.username,
            password_hash
        )
        .execute(connection_pool)
        .await
        .expect("Failed to create test user");
    }
}

pub struct TestApp {
    pub address: String,
    pub connection_pool: PgPool,
    pub email_server: wiremock::MockServer,
    pub port: u16,
    pub test_user: TestUser,
    pub api_client: reqwest::Client,
    pub email_client: EmailClient,
}

impl TestApp {
    pub async fn spawn() -> Self {
        Lazy::force(&TRACING);

        let email_server = MockServer::start().await;
        let configuration = {
            let mut c = get_configuration().expect("Failed to read configuration");
            c.database.database_name = Uuid::new_v4().to_string();
            c.application.port = 0;
            c.email_client.base_url = email_server.uri();
            c
        };
        let connection_pool = configure_database(&configuration.database).await;
        let email_client = EmailClient::build(configuration.email_client.clone()).unwrap();
        let application = Application::build(configuration)
            .await
            .expect("Failed to build application");
        let local_addr = application.local_addr();
        let port = local_addr
            .split(":")
            .last()
            .unwrap()
            .parse::<u16>()
            .unwrap();
        let address = format!("http://{}", application.local_addr());
        let test_user = TestUser::generate();
        test_user.store(&connection_pool).await;
        let api_client = reqwest::Client::builder()
            .redirect(reqwest::redirect::Policy::none())
            .cookie_store(true)
            .build()
            .unwrap();
        let app = TestApp {
            address,
            connection_pool,
            email_server,
            port,
            test_user,
            api_client,
            email_client,
        };

        tokio::spawn(application.run_until_stopped());

        app
    }

    pub async fn dispatch_all_pending_emails(&self) {
        loop {
            if let ExecutionOutcome::EmptyQueue =
                try_execute_task(&self.connection_pool, &self.email_client)
                    .await
                    .unwrap()
            {
                break;
            }
        }
    }

    pub fn get_confirmation_links(&self, request: &wiremock::Request) -> ConfirmationLinks {
        let body: serde_json::Value = serde_json::from_slice(&request.body).unwrap();
        let get_link = |s: &str| {
            let links: Vec<_> = LinkFinder::new()
                .links(s)
                .filter(|l| *l.kind() == linkify::LinkKind::Url)
                .collect();
            assert_eq!(links.len(), 1);
            let raw_link = links[0].as_str();
            let mut confirmation_link = reqwest::Url::parse(raw_link).unwrap();
            assert_eq!(confirmation_link.host_str().unwrap(), "127.0.0.1");
            confirmation_link.set_port(Some(self.port)).unwrap();
            confirmation_link
        };

        let html = get_link(body["html"].as_str().unwrap());
        let text = get_link(body["text"].as_str().unwrap());
        ConfirmationLinks { html, text }
    }

    pub async fn get_login_html(&self) -> String {
        self.api_client
            .get(format!("{}/login", &self.address))
            .send()
            .await
            .expect("Failed to execute request")
            .text()
            .await
            .unwrap()
    }

    pub async fn get_admin_dashboard(&self) -> reqwest::Response {
        self.api_client
            .get(format!("{}/admin/dashboard", &self.address))
            .send()
            .await
            .expect("Failed to execute request")
    }

    pub async fn get_admin_dashboard_html(&self) -> String {
        self.get_admin_dashboard().await.text().await.unwrap()
    }

    pub async fn get_change_password(&self) -> reqwest::Response {
        self.api_client
            .get(format!("{}/admin/password", &self.address))
            .send()
            .await
            .expect("Failed to execute request")
    }

    pub async fn get_change_password_html(&self) -> String {
        self.get_change_password().await.text().await.unwrap()
    }

    pub async fn post_subscriptions(&self, body: String) -> reqwest::Response {
        self.api_client
            .post(format!("{}/subscriptions", self.address))
            .header("Content-Type", "application/x-www-form-urlencoded")
            .body(body)
            .send()
            .await
            .expect("Failed to execute request")
    }

    pub async fn get_newsletter_form(&self) -> reqwest::Response {
        self.api_client
            .get(format!("{}/admin/password", &self.address))
            .send()
            .await
            .expect("Failed to execute request")
    }

    pub async fn get_newsletter_form_html(&self) -> String {
        self.get_newsletter_form().await.text().await.unwrap()
    }

    pub async fn post_newsletters<Body>(&self, body: &Body) -> reqwest::Response
    where
        Body: serde::Serialize,
    {
        self.api_client
            .post(format!("{}/admin/newsletters", self.address))
            .form(body)
            .send()
            .await
            .expect("Failed to execute request")
    }

    pub async fn post_login<Body>(&self, body: &Body) -> reqwest::Response
    where
        Body: serde::Serialize,
    {
        self.api_client
            .post(format!("{}/login", self.address))
            .form(body)
            .send()
            .await
            .expect("failed to execute request")
    }

    pub async fn admin_login(&self) {
        let login_body = serde_json::json!({
            "username": self.test_user.username,
            "password": self.test_user.password
        });
        self.post_login(&login_body).await;
    }

    pub async fn post_logout(&self) -> reqwest::Response {
        self.api_client
            .post(format!("{}/admin/logout", self.address))
            .send()
            .await
            .expect("failed to execute request")
    }

    pub async fn post_change_password<Body>(&self, body: &Body) -> reqwest::Response
    where
        Body: serde::Serialize,
    {
        self.api_client
            .post(format!("{}/admin/password", self.address))
            .form(body)
            .send()
            .await
            .expect("failed to execute request")
    }
}

async fn configure_database(config: &DatabaseSettings) -> PgPool {
    let mut connection = PgConnection::connect_with(&config.without_db())
        .await
        .expect("Failed to connect to Postgres");
    connection
        .execute(format!(r#"CREATE DATABASE "{}";"#, config.database_name).as_ref())
        .await
        .expect("Failed to create the database");

    let connection_pool = PgPool::connect_with(config.with_db())
        .await
        .expect("Failed to connect to Postgres");
    sqlx::migrate!("./migrations")
        .run(&connection_pool)
        .await
        .expect("Failed to migrate the database");

    connection_pool
}

pub fn assert_is_redirect_to(response: &reqwest::Response, location: &str) {
    assert_eq!(response.status().as_u16(), 303);
    assert_eq!(response.headers().get("Location").unwrap(), location);
}