use anyhow::Result;
use bollard::query_parameters::CreateImageOptionsBuilder;
use bollard::secret::{
    ContainerCreateBody, ContainerInspectResponse, ContainerState, CreateImageInfo, Health,
    HealthConfig, HealthStatusEnum, HostConfig, PortBinding,
};
use bollard::Docker;
use futures_util::{FutureExt, StreamExt as _};
use sqlx::migrate::MigrateDatabase;
use sqlx::{Connection, PgConnection};
use std::net::SocketAddr;
use std::path::Path;
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::OnceCell;
use tokio::task::JoinHandle;
use tokio::time::sleep;
use tracing::{debug, trace};
use zero_to_axum::{conf, Conf, ZeroToAxum};

static SHARED_DB: OnceCell<Arc<TestDb>> = OnceCell::const_new();
async fn get_shared_db() -> Arc<TestDb> {
    SHARED_DB
        .get_or_init(|| async { Arc::new(TestDb::spawn().await) })
        .await
        .clone()
}

pub struct TestServer {
    server_task_handle: JoinHandle<()>,
    addr: SocketAddr,
    db: Arc<TestDb>,
}

impl TestServer {
    pub async fn spawn() -> TestServer {
        debug!("start test server");

        // TODO: allow per-test DBs in some cases
        // let db = TestDb::spawn().await;
        // TODO: share test server between test file, somehow?
        let db = get_shared_db().await;
        let url = dbg!(db.get_url());

        let server = ZeroToAxum::serve(Conf {
            app: conf::App {
                listen: "[::]:0".parse().unwrap(),
            },
            database: conf::Database { url },
            debug: true,
        })
        .await
        .unwrap();
        let addr = server.local_addr();
        let server_task_handle = tokio::spawn(server.map(|res| res.unwrap()));
        debug!(?addr, "test server spawned");

        TestServer {
            server_task_handle,
            addr,
            db,
        }
    }

    /// format a URL for the given path
    pub fn url(&self, path: &str) -> String {
        format!("http://{}{path}", self.addr)
    }

    /// Request a graceful shutdown and then wait for shutdown to complete
    pub async fn shutdown(self) -> Result<()> {
        self.server_task_handle.abort();
        let _ = self.server_task_handle.await;

        self.db.stop().await;

        Ok(())
    }
}

const TEST_DB_IMAGE_NAME: &str = "postgres";
const TEST_DB_SUPERUSER: &str = "postgres";
const TEST_DB_SUPERUSER_PASS: &str = "password";
const TEST_DB_APP_USER: &str = "app";
const TEST_DB_APP_PASS: &str = "apppass";
const TEST_DB_APP_NAME: &str = "ztoa";

pub struct TestDb {
    docker: Docker,
    // image_id: String,
    container: bollard::secret::ContainerInspectResponse,
}

impl TestDb {
    pub async fn spawn() -> Self {
        let docker = Docker::connect_with_local_defaults().expect("connect to docker daemon");

        let docker = docker.negotiate_version().await.unwrap();

        let version = docker.version().await.unwrap();

        trace!("version: {version:?}");

        let mut image_id = None;

        // check for image
        if let Ok(image) = docker.inspect_image(TEST_DB_IMAGE_NAME).await {
            image_id = Some(image.id.unwrap());
        }

        // build docker image from docker file
        // let mut image_id = None;
        // {
        //     let filename = "Dockerfile.db";
        //     let image_options = bollard::query_parameters::BuildImageOptionsBuilder::default()
        //         .dockerfile(filename)
        //         .rm(true)
        //         .build();

        //     let archive_bytes = {
        //         let mut archive = tar::Builder::new(Vec::new());
        //         archive.append_path(filename).unwrap();
        //         archive.into_inner().unwrap()
        //     };

        //     let mut image_build_stream = docker.build_image(
        //         image_options,
        //         None,
        //         Some(http_body_util::Either::Left(http_body_util::Full::new(
        //             archive_bytes.into(),
        //         ))),
        //     );

        //     while let Some(msg) = image_build_stream.next().await {
        //         info!("Message: {msg:?}");

        //         if let Ok(BuildInfo {
        //             aux: Some(ImageId { id: Some(id) }),
        //             ..
        //         }) = msg
        //         {
        //             trace!("Image ID: {id}");
        //             image_id = Some(id);
        //         }
        //     }
        // }
        // let image_id = image_id.expect("get image id for built docker image");

        // pull image
        if image_id.is_none() {
            let image_opts = CreateImageOptionsBuilder::new()
                .from_image(TEST_DB_IMAGE_NAME)
                .build();

            trace!(?image_opts, "pull image");
            let mut image_create_stream = docker.create_image(Some(image_opts), None, None);

            while let Some(msg) = image_create_stream.next().await {
                trace!("Message: {msg:?}");

                if let Ok(CreateImageInfo { id: Some(id), .. }) = msg {
                    trace!("Image ID: {id}");
                    image_id = Some(id);
                }
            }
        }

        let image_id = image_id.expect("get image id for built docker image");

        // create and start docker container
        let container_id;
        {
            let container_config = ContainerCreateBody {
                image: Some(image_id.clone()),
                exposed_ports: Some([("5432/tcp".to_string(), [].into())].into()),
                host_config: Some(HostConfig {
                    port_bindings: Some(
                        [(
                            "5432/tcp".to_string(),
                            Some(vec![PortBinding {
                                host_ip: Some("127.0.0.1".to_string()),
                                host_port: None, // auto-assign
                            }]),
                        )]
                        .into(),
                    ),
                    ..Default::default()
                }),
                env: Some(vec![
                    format!("POSTGRES_USER={TEST_DB_SUPERUSER}"),
                    format!("POSTGRES_PASSWORD={TEST_DB_SUPERUSER_PASS}"),
                ]),
                healthcheck: Some(HealthConfig {
                    test: Some(vec!["pg_isready -U postgres || exit 1".to_string()]),
                    // nano seconds
                    interval: Some(1 * 1000 * 1000 * 1000),
                    timeout: Some(5 * 1000 * 1000 * 1000),
                    retries: Some(5 * 1000 * 1000 * 1000),
                    ..Default::default()
                }),
                ..Default::default()
            };

            trace!("create container");
            bollard::secret::ContainerCreateResponse {
                id: container_id,
                ..
            } = docker
                .create_container(
                    None::<bollard::query_parameters::CreateContainerOptions>,
                    container_config,
                )
                .await
                .unwrap();

            trace!("start container");
            docker
                .start_container(
                    &container_id,
                    None::<bollard::query_parameters::StartContainerOptions>,
                )
                .await
                .unwrap();
        }

        // wait for container to be started
        let container = loop {
            trace!("inspect container");
            let container = docker
                .inspect_container(
                    &container_id,
                    None::<bollard::query_parameters::InspectContainerOptions>,
                )
                .await
                .unwrap();

            if let ContainerInspectResponse {
                state:
                    Some(ContainerState {
                        health:
                            Some(Health {
                                status: Some(status),
                                ..
                            }),
                        ..
                    }),
                ..
            } = &container
            {
                trace!("status: {status:?}");
                if *status == HealthStatusEnum::HEALTHY {
                    break container;
                }
            }

            sleep(Duration::from_secs(2)).await;
        };

        let db = TestDb {
            docker,
            // image_id,
            container,
        };

        // setup app db
        {
            let mut conn = PgConnection::connect(&db.get_superuser_url())
                .await
                .unwrap();

            // create application user
            // Note: In general, string formtting a query is bad practice, but it's required here.
            sqlx::query(&format!(
                "CREATE USER {TEST_DB_APP_USER} WITH PASSWORD '{TEST_DB_APP_PASS}';"
            ))
            .execute(&mut conn)
            .await
            .unwrap();

            // grant privs to app user
            // Note: In general, string formtting a query is bad practice, but it's required here.
            sqlx::query(&format!("ALTER USER {TEST_DB_APP_USER} CREATEDB;"))
                .execute(&mut conn)
                .await
                .unwrap();
        }

        // create test db
        sqlx::Postgres::create_database(&dbg!(db.get_url()))
            .await
            .unwrap();

        let mut conn = PgConnection::connect(&db.get_url()).await.unwrap();

        // run migrations on test db
        let m = sqlx::migrate::Migrator::new(Path::new("./migrations"))
            .await
            .unwrap();
        m.run(&mut conn).await.unwrap();

        db
    }

    /// Get the authenticated URL for accessing the test DB from the host.
    pub fn get_url(&self) -> String {
        let binding = self
            .container
            .network_settings
            .as_ref()
            .unwrap()
            .ports
            .as_ref()
            .unwrap()
            .get("5432/tcp")
            .as_ref()
            .unwrap()
            .as_ref()
            .unwrap()
            .first()
            .unwrap();
        let host_ip = binding.host_ip.as_ref().unwrap().clone();
        let host_port = binding.host_port.as_ref().unwrap().clone();
        format!("postgres://{TEST_DB_APP_USER}:{TEST_DB_APP_PASS}@{host_ip}:{host_port}/{TEST_DB_APP_NAME}")
    }

    /// Get the superuser-authenticated URL for accessing the `postgres` db from the host.
    fn get_superuser_url(&self) -> String {
        let binding = self
            .container
            .network_settings
            .as_ref()
            .unwrap()
            .ports
            .as_ref()
            .unwrap()
            .get("5432/tcp")
            .as_ref()
            .unwrap()
            .as_ref()
            .unwrap()
            .first()
            .unwrap();
        let host_ip = binding.host_ip.as_ref().unwrap().clone();
        let host_port = binding.host_port.as_ref().unwrap().clone();
        format!("postgres://{TEST_DB_SUPERUSER}:{TEST_DB_SUPERUSER_PASS}@{host_ip}:{host_port}/postgres")
    }

    pub async fn stop(&self) {
        self.docker
            .stop_container(
                &self.container.id.as_deref().unwrap(),
                #[allow(deprecated)] // is deprecated, but also required
                None::<bollard::container::StopContainerOptions>,
            )
            .await
            .unwrap();

        self.docker
            .remove_container(
                &self.container.id.as_deref().unwrap(),
                None::<bollard::query_parameters::RemoveContainerOptions>,
            )
            .await
            .unwrap();

        // // TODO: images seem like they might be reused, this is probably a bad idea, but it seems to work?
        // let _ = self
        //     .docker
        //     .remove_image(
        //         &self.image_id,
        //         None::<bollard::query_parameters::RemoveImageOptions>,
        //         None,
        //     )
        //     .await;
    }
}