use std::sync::Arc;

use axum::{
    body::Body,
    http::{Request, StatusCode},
    routing::get,
    Json,
    Router,
};
use base64::{engine::general_purpose::STANDARD, Engine};
use chrono::{DateTime, Utc};
use serde_json::json;
use sqlx::any::install_default_drivers;
use tower::ServiceExt;
use tokio::net::TcpListener;

use mikebase::{
    build_router,
    config::{AppConfig, AuthConfig, DatabaseConfig, ImportConfig, S3Config, ServerConfig},
    db::Database,
    models::new_uuid,
    storage::S3Storage,
    AppState,
};

// ── Helpers ───────────────────────────────────────────────────────────────────

async fn test_state() -> AppState {
    test_state_with_s3(
        "http://localhost:19999".to_string(),
        "http://localhost:19999/test-bucket".to_string(),
    )
    .await
}

async fn test_state_with_s3(s3_endpoint: String, s3_public_url: String) -> AppState {
    install_default_drivers();
    let pool = sqlx::pool::PoolOptions::<sqlx::Any>::new()
        .max_connections(1)
        .connect("sqlite::memory:")
        .await
        .unwrap();
    let db = Database { pool };
    db.migrate().await.unwrap();

    let cfg = Arc::new(AppConfig {
        s3: S3Config {
            endpoint: s3_endpoint,
            region: "us-east-1".to_string(),
            bucket: "test-bucket".to_string(),
            access_key: "test".to_string(),
            secret_key: "test".to_string(),
            public_url: s3_public_url,
        },
        database: DatabaseConfig { url: "sqlite::memory:".to_string() },
        server: ServerConfig::default(),
        auth: Some(AuthConfig {
            username: "admin".to_string(),
            password: "secret".to_string(),
        }),
        import: ImportConfig {
            allowed_hosts: vec!["smutba.se".to_string(), "localhost".to_string(), "127.0.0.1".to_string()],
        },
    });

    let storage = S3Storage::new(&cfg);
    AppState { db, storage, cfg }
}

async fn spawn_mock_s3_server() -> (String, tokio::task::JoinHandle<()>) {
    async fn ok() -> StatusCode {
        StatusCode::OK
    }

    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
    let addr = listener.local_addr().unwrap();
    let base = format!("http://{}", addr);

    let app = Router::new()
        .route("/", get(ok))
        .route("/{*path}", axum::routing::any(ok));

    let handle = tokio::spawn(async move {
        axum::serve(listener, app).await.unwrap();
    });

    (base, handle)
}

async fn spawn_legacy_source_server() -> (String, tokio::task::JoinHandle<()>) {
    async fn image_new() -> ([(&'static str, &'static str); 1], &'static [u8]) {
        ([ ("content-type", "image/png") ], b"PNGDATA")
    }

    async fn image_dup() -> ([(&'static str, &'static str); 1], &'static [u8]) {
        ([ ("content-type", "image/png") ], b"PNGDATA2")
    }

    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
    let addr = listener.local_addr().unwrap();
    let base = format!("http://{}", addr);

    let payload_base = base.clone();
    let app = Router::new()
        .route(
            "/emoji/json/",
            get(move || {
                let payload_base = payload_base.clone();
                async move {
                    Json(json!({
                        "emotes": [
                            {
                                "name": "legacy_new",
                                "url": format!("{}/images/new.png", payload_base),
                                "created": "2020-01-01T00:00:00+00:00",
                                "modified": "2020-02-02T00:00:00+00:00"
                            },
                            {
                                "name": "legacy_duplicate",
                                "url": format!("{}/images/duplicate.png", payload_base),
                                "created": "2021-01-01T00:00:00+00:00",
                                "modified": "2021-01-02T00:00:00+00:00"
                            }
                        ]
                    }))
                }
            }),
        )
        .route("/images/new.png", get(image_new))
        .route("/images/duplicate.png", get(image_dup));

    let handle = tokio::spawn(async move {
        axum::serve(listener, app).await.unwrap();
    });

    (base, handle)
}

fn auth_header() -> String {
    format!("Basic {}", STANDARD.encode("admin:secret"))
}

fn wrong_auth_header() -> String {
    format!("Basic {}", STANDARD.encode("admin:wrong"))
}

async fn response_json(body: Body) -> serde_json::Value {
    let bytes = axum::body::to_bytes(body, usize::MAX).await.unwrap();
    serde_json::from_slice(&bytes).unwrap()
}

/// Build a minimal multipart/form-data body.
fn multipart_body(boundary: &str, parts: &[(&str, Option<&str>, &[u8])]) -> Vec<u8> {
    let mut body = Vec::new();
    for (name, filename, data) in parts {
        let disp = match filename {
            Some(fname) => format!(
                "Content-Disposition: form-data; name=\"{name}\"; filename=\"{fname}\"\r\nContent-Type: application/octet-stream"
            ),
            None => format!("Content-Disposition: form-data; name=\"{name}\""),
        };
        body.extend_from_slice(format!("--{boundary}\r\n{disp}\r\n\r\n").as_bytes());
        body.extend_from_slice(data);
        body.extend_from_slice(b"\r\n");
    }
    body.extend_from_slice(format!("--{boundary}--\r\n").as_bytes());
    body
}

// ── Public routes ─────────────────────────────────────────────────────────────

#[tokio::test]
async fn health_returns_200() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(Request::builder().uri("/health").body(Body::empty()).unwrap())
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::OK);
    let json = response_json(resp.into_body()).await;
    assert_eq!(json["status"], "ok");
}

#[tokio::test]
async fn root_returns_html() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(Request::builder().uri("/").body(Body::empty()).unwrap())
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::OK);
    assert!(resp
        .headers()
        .get("content-type")
        .unwrap()
        .to_str()
        .unwrap()
        .contains("text/html"));
}

#[tokio::test]
async fn list_emotes_empty() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(Request::builder().uri("/json").body(Body::empty()).unwrap())
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::OK);
    let json = response_json(resp.into_body()).await;
    assert_eq!(json["emotes"], serde_json::json!([]));
}

#[tokio::test]
async fn list_emotes_returns_seeded_data() {
    let state = test_state().await;
    let id = new_uuid();
    state
        .db
        .create_emote(&id, "wave", Some("hello"), "emoji/wave.png")
        .await
        .unwrap();

    let resp = build_router(state)
        .oneshot(Request::builder().uri("/json").body(Body::empty()).unwrap())
        .await
        .unwrap();

    assert_eq!(resp.status(), StatusCode::OK);
    let json = response_json(resp.into_body()).await;
    assert_eq!(json["emotes"].as_array().unwrap().len(), 1);
    assert_eq!(json["emotes"][0]["name"], "wave");
}

// ── Auth middleware ───────────────────────────────────────────────────────────

#[tokio::test]
async fn manage_without_credentials_returns_401() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(Request::builder().uri("/manage").body(Body::empty()).unwrap())
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::UNAUTHORIZED);
}

#[tokio::test]
async fn manage_with_wrong_credentials_returns_401() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(
            Request::builder()
                .uri("/manage")
                .header("authorization", wrong_auth_header())
                .body(Body::empty())
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::UNAUTHORIZED);
}

#[tokio::test]
async fn manage_with_correct_credentials_returns_200() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(
            Request::builder()
                .uri("/manage")
                .header("authorization", auth_header())
                .body(Body::empty())
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::OK);
}

#[tokio::test]
async fn manage_emotes_requires_auth() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(
            Request::builder()
                .uri("/manage/emotes")
                .body(Body::empty())
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::UNAUTHORIZED);
}

#[tokio::test]
async fn manage_import_requires_auth() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(
            Request::builder()
                .method("POST")
                .uri("/manage/import")
                .header("content-type", "application/json")
                .body(Body::from(r#"{"source_url":"https://smutba.se/emoji/json/"}"#))
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::UNAUTHORIZED);
}

#[tokio::test]
async fn manage_import_rejects_non_allowlisted_host() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(
            Request::builder()
                .method("POST")
                .uri("/manage/import")
                .header("authorization", auth_header())
                .header("content-type", "application/json")
                .body(Body::from(r#"{"source_url":"https://example.com/emoji/json/"}"#))
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
}

#[tokio::test]
async fn manage_import_mirrors_and_skips_duplicates() {
    let (legacy_base, server_handle) = spawn_legacy_source_server().await;
    let (s3_base, s3_handle) = spawn_mock_s3_server().await;

    let state = test_state_with_s3(s3_base.clone(), format!("{}/test-bucket", s3_base)).await;
    // Pre-seed one duplicate emote name.
    let existing_id = new_uuid();
    state
        .db
        .create_emote(&existing_id, "legacy_duplicate", None, "emoji/existing.png")
        .await
        .unwrap();

    let app = build_router(state.clone());
    let resp = app
        .oneshot(
            Request::builder()
                .method("POST")
                .uri("/manage/import")
                .header("authorization", auth_header())
                .header("content-type", "application/json")
                .body(Body::from(format!(
                    "{{\"source_url\":\"{}/emoji/json/\"}}",
                    legacy_base
                )))
                .unwrap(),
        )
        .await
        .unwrap();

    assert_eq!(resp.status(), StatusCode::OK);
    let json = response_json(resp.into_body()).await;
    assert_eq!(json["total"], 2);
    assert_eq!(json["imported"], 1);
    assert_eq!(json["skipped"], 1);
    assert_eq!(json["failed"], 0);

    let rows = state.db.list_emotes().await.unwrap();
    let imported = rows.iter().find(|r| r.name == "legacy_new").unwrap();
    let created = DateTime::parse_from_rfc3339(&imported.created)
        .unwrap()
        .with_timezone(&Utc)
        .to_rfc3339();
    let modified = DateTime::parse_from_rfc3339(&imported.modified)
        .unwrap()
        .with_timezone(&Utc)
        .to_rfc3339();
    assert_eq!(created, "2020-01-01T00:00:00+00:00");
    assert_eq!(modified, "2020-02-02T00:00:00+00:00");

    server_handle.abort();
    s3_handle.abort();
}

#[tokio::test]
async fn manage_import_dry_run_does_not_persist() {
    let (legacy_base, server_handle) = spawn_legacy_source_server().await;
    let (s3_base, s3_handle) = spawn_mock_s3_server().await;

    let state = test_state_with_s3(s3_base.clone(), format!("{}/test-bucket", s3_base)).await;
    // Pre-seed one duplicate so we can verify would_skip detection.
    let existing_id = new_uuid();
    state
        .db
        .create_emote(&existing_id, "legacy_duplicate", None, "emoji/existing.png")
        .await
        .unwrap();

    let app = build_router(state.clone());
    let body = format!(
        "{{\"source_url\":\"{}/emoji/json/\",\"dry_run\":true}}",
        legacy_base
    );
    let resp = app
        .oneshot(
            Request::builder()
                .method("POST")
                .uri("/manage/import")
                .header("authorization", auth_header())
                .header("content-type", "application/json")
                .body(Body::from(body))
                .unwrap(),
        )
        .await
        .unwrap();

    assert_eq!(resp.status(), StatusCode::OK);
    let json = response_json(resp.into_body()).await;
    assert_eq!(json["dry_run"], true);
    assert_eq!(json["total"], 2);
    assert_eq!(json["imported"], 1);
    assert_eq!(json["skipped"], 1);
    assert_eq!(json["failed"], 0);

    let results = json["results"].as_array().unwrap();
    let new_result = results.iter().find(|r| r["name"] == "legacy_new").unwrap();
    assert_eq!(new_result["status"], "would_import");
    let dup_result = results.iter().find(|r| r["name"] == "legacy_duplicate").unwrap();
    assert_eq!(dup_result["status"], "would_skip");

    // Nothing new should have been written to the DB.
    let rows = state.db.list_emotes().await.unwrap();
    assert_eq!(rows.len(), 1, "dry-run must not insert any rows");
    assert_eq!(rows[0].name, "legacy_duplicate");

    server_handle.abort();
    s3_handle.abort();
}

// ── POST /emotes input validation ─────────────────────────────────────────────

#[tokio::test]
async fn create_emote_without_auth_returns_401() {
    let boundary = "testboundary";
    let body = multipart_body(boundary, &[("name", None, b"myemote")]);
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(
            Request::builder()
                .method("POST")
                .uri("/emotes")
                .header("content-type", format!("multipart/form-data; boundary={boundary}"))
                .body(Body::from(body))
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::UNAUTHORIZED);
}

#[tokio::test]
async fn create_emote_missing_name_returns_400() {
    let boundary = "testboundary";
    let body = multipart_body(boundary, &[("file", Some("cat.png"), b"\x89PNG")]);
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(
            Request::builder()
                .method("POST")
                .uri("/emotes")
                .header("authorization", auth_header())
                .header("content-type", format!("multipart/form-data; boundary={boundary}"))
                .body(Body::from(body))
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
    let json = response_json(resp.into_body()).await;
    assert!(json["error"].as_str().unwrap().contains("name"));
}

#[tokio::test]
async fn create_emote_missing_file_returns_400() {
    let boundary = "testboundary";
    let body = multipart_body(boundary, &[("name", None, b"myemote")]);
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(
            Request::builder()
                .method("POST")
                .uri("/emotes")
                .header("authorization", auth_header())
                .header("content-type", format!("multipart/form-data; boundary={boundary}"))
                .body(Body::from(body))
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
    let json = response_json(resp.into_body()).await;
    assert!(json["error"].as_str().unwrap().contains("file"));
}

// ── PUT /emotes/{uuid} ────────────────────────────────────────────────────────

#[tokio::test]
async fn update_emote_not_found_returns_404() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(
            Request::builder()
                .method("PUT")
                .uri("/emotes/no-such-uuid")
                .header("authorization", auth_header())
                .header("content-type", "application/json")
                .body(Body::from(r#"{"name":"new"}"#))
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::NOT_FOUND);
}

#[tokio::test]
async fn update_emote_ok() {
    let state = test_state().await;
    let id = new_uuid();
    state
        .db
        .create_emote(&id, "original", None, "emoji/x.png")
        .await
        .unwrap();

    let resp = build_router(state)
        .oneshot(
            Request::builder()
                .method("PUT")
                .uri(format!("/emotes/{id}"))
                .header("authorization", auth_header())
                .header("content-type", "application/json")
                .body(Body::from(r#"{"name":"updated"}"#))
                .unwrap(),
        )
        .await
        .unwrap();

    assert_eq!(resp.status(), StatusCode::OK);
    let json = response_json(resp.into_body()).await;
    assert_eq!(json["name"], "updated");
}

// ── DELETE /emotes/{uuid} ─────────────────────────────────────────────────────

#[tokio::test]
async fn delete_emote_not_found_returns_404() {
    let app = build_router(test_state().await);
    let resp = app
        .oneshot(
            Request::builder()
                .method("DELETE")
                .uri("/emotes/no-such-uuid")
                .header("authorization", auth_header())
                .body(Body::empty())
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(resp.status(), StatusCode::NOT_FOUND);
}

#[tokio::test]
async fn delete_emote_ok() {
    let state = test_state().await;
    let id = new_uuid();
    state
        .db
        .create_emote(&id, "todelete", None, "emoji/gone.png")
        .await
        .unwrap();

    // S3 delete will fail against the fake endpoint, but it is best-effort.
    let resp = build_router(state)
        .oneshot(
            Request::builder()
                .method("DELETE")
                .uri(format!("/emotes/{id}"))
                .header("authorization", auth_header())
                .body(Body::empty())
                .unwrap(),
        )
        .await
        .unwrap();

    assert_eq!(resp.status(), StatusCode::NO_CONTENT);
}