use axum::extract::{DefaultBodyLimit, State};
use axum::http::{header, HeaderMap, Request, StatusCode};
use axum::response::IntoResponse;
use axum::{body::Body, routing::post, Router};
use hemx_axum::{
    interactions, runtime_js, runtime_js_hash, runtime_js_path, runtime_js_route_path,
    runtime_js_script_src, runtime_js_source, DispatchRejection, EffectResponse, Form,
    HandlerErrorContext, HandlerFailure, InteractionForm, InteractionFormRejection,
    InteractionRequest, IntoHandlerFailure, PageMode, PageRequest, PageResponse, HEMX_CONTENT_TYPE,
    HEMX_FINGERPRINT_HEADER, HEMX_PARTIAL_HEADER, HEMX_RUNTIME_CONTENT_TYPE, HEMX_TITLE_HEADER,
};
use hemx_core::{push, BuildFingerprint, Handle, IntoEffect, SafeHtml, Slot};
use scraper::{Html, Selector};
use std::sync::atomic::{AtomicUsize, Ordering};
use tower::ServiceExt;

static MUTATION_CALLS: AtomicUsize = AtomicUsize::new(0);

async fn bounded_mutation(_: InteractionRequest) -> StatusCode {
    MUTATION_CALLS.fetch_add(1, Ordering::SeqCst);
    StatusCode::NO_CONTENT
}

#[tokio::test]
async fn interaction_boundary_honors_media_type_and_host_body_limit() {
    // test req: security/003
    MUTATION_CALLS.store(0, Ordering::SeqCst);
    let app = Router::new()
        .route("/mutate", post(bounded_mutation))
        .layer(DefaultBodyLimit::max(32));

    let unsupported = app
        .clone()
        .oneshot(
            Request::post("/mutate")
                .header(header::CONTENT_TYPE, "application/json")
                .body(Body::from(r#"{"__h":"1"}"#))
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(unsupported.status(), StatusCode::UNSUPPORTED_MEDIA_TYPE);
    assert_eq!(MUTATION_CALLS.load(Ordering::SeqCst), 0);

    let oversized = app
        .clone()
        .oneshot(
            Request::post("/mutate")
                .header(header::CONTENT_TYPE, "application/x-www-form-urlencoded")
                .body(Body::from(format!("__h=1&value={}", "x".repeat(64))))
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(oversized.status(), StatusCode::PAYLOAD_TOO_LARGE);
    assert_eq!(MUTATION_CALLS.load(Ordering::SeqCst), 0);

    let accepted = app
        .oneshot(
            Request::post("/mutate")
                .header(
                    header::CONTENT_TYPE,
                    "application/x-www-form-urlencoded; charset=utf-8",
                )
                .body(Body::from("__h=1"))
                .unwrap(),
        )
        .await
        .unwrap();
    assert_eq!(accepted.status(), StatusCode::NO_CONTENT);
    assert_eq!(MUTATION_CALLS.load(Ordering::SeqCst), 1);
}

fn selector(value: &str) -> Selector {
    Selector::parse(value).expect("test selector parses")
}

#[derive(Clone, Copy, Debug, Eq, PartialEq)]
struct ProjectId(u32);

impl std::str::FromStr for ProjectId {
    type Err = std::num::ParseIntError;

    fn from_str(value: &str) -> Result<Self, Self::Err> {
        value.parse().map(ProjectId)
    }
}

struct OpenProject {
    project_id: ProjectId,
}

impl hemx_core::FromForm for OpenProject {
    fn from_form_fields(fields: &[(String, String)]) -> Result<Self, hemx_core::FormError> {
        let Some(value) = fields
            .iter()
            .find_map(|(name, value)| (name == "project_id").then_some(value.as_str()))
        else {
            return Err(hemx_core::FormError::new("missing form field `project_id`"));
        };
        Ok(Self {
            project_id: value
                .parse()
                .map_err(|_| hemx_core::FormError::new("invalid form field `project_id`"))?,
        })
    }
}

#[test]
fn page_mode_detects_partial_header() {
    let mut headers = HeaderMap::new();
    assert_eq!(PageMode::from_headers(&headers), PageMode::Full);

    headers.insert(HEMX_PARTIAL_HEADER, "true".parse().unwrap());
    assert_eq!(PageMode::from_headers(&headers), PageMode::Partial);
}

#[test]
fn page_request_wraps_full_pages_and_leaves_partials_unwrapped() {
    // req: test/005
    assert!(!PageRequest {
        mode: PageMode::Full
    }
    .is_partial());
    assert!(PageRequest {
        mode: PageMode::Partial
    }
    .is_partial());
    let full = PageRequest {
        mode: PageMode::Full,
    }
    .page("<main data-page=\"docs\">Docs</main>", |content| {
        format!("<html><body data-shell=\"docs\">{content}</body></html>")
    });
    assert_eq!(full.mode, PageMode::Full);
    let full_document = Html::parse_document(&full.html);
    assert_eq!(
        full_document
            .select(&selector(
                "body[data-shell=\"docs\"] main[data-page=\"docs\"]"
            ))
            .count(),
        1
    );

    let partial = PageRequest {
        mode: PageMode::Partial,
    }
    .page("<main data-page=\"docs\">Docs</main>", |content| {
        format!("<html><body data-shell=\"docs\">{content}</body></html>")
    });
    assert_eq!(partial.mode, PageMode::Partial);
    let partial_fragment = Html::parse_fragment(&partial.html);
    assert_eq!(
        partial_fragment
            .select(&selector("main[data-page=\"docs\"]"))
            .count(),
        1
    );
    assert_eq!(
        partial_fragment
            .select(&selector("body[data-shell=\"docs\"]"))
            .count(),
        0
    );
}

#[test]
fn page_request_wraps_safe_html_full_pages_and_leaves_partials_unwrapped() {
    // req: axum_integration/001 req: html_safety/001 req: html_safety/002 req: test/005
    let full = PageRequest {
        mode: PageMode::Full,
    }
    .page_html(
        SafeHtml::trusted("<main data-page=\"docs\">Docs</main>"),
        |content| {
            SafeHtml::trusted(format!(
                "<html><body data-shell=\"docs\">{content}</body></html>"
            ))
        },
    );
    assert_eq!(full.mode, PageMode::Full);
    let full_document = Html::parse_document(&full.html);
    assert_eq!(
        full_document
            .select(&selector(
                "body[data-shell=\"docs\"] main[data-page=\"docs\"]"
            ))
            .count(),
        1
    );

    let partial = PageRequest {
        mode: PageMode::Partial,
    }
    .page_html(
        SafeHtml::trusted("<main data-page=\"docs\">Docs</main>"),
        |content| {
            SafeHtml::trusted(format!(
                "<html><body data-shell=\"docs\">{content}</body></html>"
            ))
        },
    );
    assert_eq!(partial.mode, PageMode::Partial);
    let partial_fragment = Html::parse_fragment(&partial.html);
    assert_eq!(
        partial_fragment
            .select(&selector("main[data-page=\"docs\"]"))
            .count(),
        1
    );
    assert_eq!(
        partial_fragment
            .select(&selector("body[data-shell=\"docs\"]"))
            .count(),
        0
    );
}

#[test]
fn page_response_constructors_preserve_mode_and_optional_fingerprint() {
    let full = PageResponse::full("<html>Full</html>");
    assert_eq!(full.mode, PageMode::Full);
    assert_eq!(full.html, "<html>Full</html>");
    assert_eq!(full.fingerprint, None);

    let partial = PageResponse::partial("<main>Partial</main>");
    assert_eq!(partial.mode, PageMode::Partial);
    assert_eq!(partial.html, "<main>Partial</main>");
    assert_eq!(partial.fingerprint, None);

    let fingerprint = BuildFingerprint(42);
    assert_eq!(
        partial.fingerprint(fingerprint).fingerprint,
        Some(fingerprint)
    );
    // test req: page_swap/001 req: abi/005
}

#[test]
fn partial_page_response_sets_partial_and_title_headers() {
    let response = PageResponse::partial("<main>Docs</main>")
        .title("Docs")
        .into_response();

    assert_eq!(
        response.headers()[header::CONTENT_TYPE],
        "text/html; charset=utf-8"
    );
    assert_eq!(response.headers()[HEMX_PARTIAL_HEADER], "true");
    assert_eq!(response.headers()[HEMX_TITLE_HEADER], "Docs");
}

#[test]
fn effect_response_is_wire_batch_with_fingerprint_header() {
    let response = EffectResponse::new(push("/docs"), BuildFingerprint(99)).into_response();

    assert_eq!(response.headers()[header::CONTENT_TYPE], HEMX_CONTENT_TYPE);
    assert_eq!(response.headers()[HEMX_FINGERPRINT_HEADER], "99");
}

#[test]
fn interaction_form_parses_handle_and_fields() {
    let form =
        InteractionForm::parse_urlencoded(b"__h=42&title=Hello+World&tag=a&tag=b%2Fc").unwrap();

    assert_eq!(form.handle_id, 42);
    assert_eq!(form.value("title"), Some("Hello World"));
    assert_eq!(form.values("tag").collect::<Vec<_>>(), ["a", "b/c"]);
}

#[test]
fn interaction_form_parses_typed_values() {
    // req: form/004 req: dx/003
    let form =
        InteractionForm::parse_urlencoded(b"__h=42&count=7&bad=nope").expect("form should parse");

    assert_eq!(form.parse::<u32>("count"), Some(7));
    assert_eq!(form.parse::<u32>("bad"), None);
    assert_eq!(form.parse::<u32>("missing"), None);
}

#[test]
fn interaction_form_requires_numeric_handle() {
    assert_eq!(
        InteractionForm::parse_urlencoded(b"title=Hello").unwrap_err(),
        InteractionFormRejection::MissingHandle
    );
    assert_eq!(
        InteractionForm::parse_urlencoded(b"__h=nope").unwrap_err(),
        InteractionFormRejection::InvalidHandle
    );
}

#[test]
fn interaction_form_preserves_hidden_csrf_fields_for_extractors() {
    // req: auth/004
    let form = InteractionForm::parse_urlencoded(b"__h=42&csrf_token=abc123&title=Hello").unwrap();

    assert_eq!(form.handle_id, 42);
    assert_eq!(form.value("csrf_token"), Some("abc123"));
    assert!(form.fields().iter().any(|(name, _)| name == "csrf_token"));
}

#[test]
fn interaction_request_dispatches_with_concise_handlers_helper() {
    // req: axum_integration/003 req: ceremony/001 req: dx/003
    let request = InteractionRequest::from(InteractionForm::for_handle(
        Handle::<()>::new(7),
        Vec::new(),
    ));
    let response = request
        .dispatch(
            interactions(BuildFingerprint(4))
                .on(Handle::<()>::new(7), |_| Slot::<String>::new(3).text("ok")),
        )
        .unwrap();

    assert_eq!(response.batch.fingerprint, BuildFingerprint(4));
    assert_eq!(response.batch.ops, vec![Slot::<String>::new(3).text("ok")]);
}

#[test]
fn state_interactions_starts_stateful_wiring_without_nested_closures() {
    // req: axum_integration/003 req: ceremony/001 req: dx/003
    fn ping(prefix: String) -> impl IntoEffect {
        Slot::<String>::new(3).text(format!("{prefix}: ping"))
    }

    fn open(prefix: String, input: OpenProject) -> impl IntoEffect {
        Slot::<String>::new(3).text(format!("{prefix}: {}", input.project_id.0))
    }

    let registry = || {
        hemx_axum::state_interactions(BuildFingerprint(4), "project".to_owned())
            .on_state(Handle::<()>::new(7), ping)
            .on(Handle::<()>::new(8), open)
            .into_registry()
    };

    let ping_response = InteractionRequest::from(InteractionForm::for_handle(
        Handle::<()>::new(7),
        Vec::new(),
    ))
    .dispatch(registry())
    .unwrap();
    assert_eq!(
        ping_response.batch.ops,
        vec![Slot::<String>::new(3).text("project: ping")]
    );

    let open_response = InteractionRequest::from(InteractionForm::for_handle(
        Handle::<()>::new(8),
        vec![("project_id".to_owned(), "42".to_owned())],
    ))
    .dispatch(registry())
    .unwrap();
    assert_eq!(
        open_response.batch.ops,
        vec![Slot::<String>::new(3).text("project: 42")]
    );
}

#[test]
fn interaction_request_dispatches_typed_form_inputs() {
    // req: axum_integration/003 req: form/004 req: canonical_authoring/003
    let request = InteractionRequest::from(InteractionForm::for_handle(
        Handle::<()>::new(8),
        vec![("project_id".to_owned(), "42".to_owned())],
    ));
    let response = request
        .dispatch(
            interactions(BuildFingerprint(4))
                .on_form(Handle::<()>::new(8), |input: OpenProject| {
                    Slot::<String>::new(3).text(input.project_id.0)
                }),
        )
        .unwrap();

    assert_eq!(response.batch.fingerprint, BuildFingerprint(4));
    assert_eq!(response.batch.ops, vec![Slot::<String>::new(3).text(42)]);
}

#[test]
fn interaction_request_rejects_invalid_typed_form_inputs() {
    // req: axum_integration/003 req: form/004 req: canonical_authoring/004
    let request = InteractionRequest::from(InteractionForm::for_handle(
        Handle::<()>::new(8),
        vec![("project_id".to_owned(), "nope".to_owned())],
    ));
    let rejection = request
        .dispatch(
            interactions(BuildFingerprint(4))
                .on_form(Handle::<()>::new(8), |input: OpenProject| {
                    Slot::<String>::new(3).text(input.project_id.0)
                }),
        )
        .unwrap_err();

    assert!(matches!(
        rejection,
        DispatchRejection::InvalidForm { handle_id: 8, .. }
    ));
}

#[test]
fn interaction_request_dispatches_typed_state_handlers() {
    // req: axum_integration/003 req: form/004 req: canonical_authoring/003
    fn open_project(multiplier: u32, input: OpenProject) -> impl IntoEffect {
        Slot::<String>::new(3).text(input.project_id.0 * multiplier)
    }

    let request = InteractionRequest::from(InteractionForm::for_handle(
        Handle::<()>::new(9),
        vec![("project_id".to_owned(), "21".to_owned())],
    ));
    let response = request
        .dispatch(
            interactions(BuildFingerprint(4))
                .with_state(2_u32)
                .on(Handle::<()>::new(9), open_project),
        )
        .unwrap();

    assert_eq!(response.batch.ops, vec![Slot::<String>::new(3).text(42)]);
}

#[derive(Debug)]
struct HandlerBoom;

impl std::fmt::Display for HandlerBoom {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.write_str("database unavailable")
    }
}

impl std::error::Error for HandlerBoom {}

impl IntoHandlerFailure for HandlerBoom {
    fn into_handler_failure(self, _context: HandlerErrorContext) -> HandlerFailure {
        HandlerFailure::internal(self.to_string())
    }
}

#[derive(Debug)]
struct UiFailure;

impl IntoHandlerFailure for UiFailure {
    fn into_handler_failure(self, context: HandlerErrorContext) -> HandlerFailure {
        HandlerFailure::effects(Slot::<String>::new(3).text("try again"), context)
    }
}

#[tokio::test]
async fn interaction_request_dispatches_async_typed_state_extractors() {
    // req: axum_integration/003 req: form/004 req: canonical_authoring/003
    async fn open_project(
        State(multiplier): State<u32>,
        Form(input): Form<OpenProject>,
    ) -> impl IntoEffect {
        Slot::<String>::new(3).text(input.project_id.0 * multiplier)
    }

    let request = InteractionRequest::from(InteractionForm::for_handle(
        Handle::<()>::new(10),
        vec![("project_id".to_owned(), "21".to_owned())],
    ));
    let response = request
        .dispatch_async(
            interactions(BuildFingerprint(4))
                .with_state(2_u32)
                .on_async(Handle::<()>::new(10), open_project)
                .into_registry(),
        )
        .await
        .unwrap();

    assert_eq!(response.batch.ops, vec![Slot::<String>::new(3).text(42)]);
}

#[tokio::test]
async fn interaction_request_reports_async_result_handler_errors() {
    // req: axum_integration/003 req: form/004 req: failure/003
    async fn open_project(
        State(_multiplier): State<u32>,
        Form(_input): Form<OpenProject>,
    ) -> Result<impl IntoEffect, HandlerBoom> {
        Err::<(), _>(HandlerBoom)
    }

    let request = InteractionRequest::from(InteractionForm::for_handle(
        Handle::<()>::new(11),
        vec![("project_id".to_owned(), "21".to_owned())],
    ));
    let error = request
        .dispatch_async(
            interactions(BuildFingerprint(4))
                .with_state(2_u32)
                .on_async_result(Handle::<()>::new(11), open_project)
                .into_registry(),
        )
        .await
        .unwrap_err();

    assert_eq!(
        error,
        DispatchRejection::HandlerError(HandlerFailure::Response {
            status: axum::http::StatusCode::INTERNAL_SERVER_ERROR,
            message: "database unavailable".to_owned(),
        })
    );
}

#[tokio::test]
async fn interaction_request_maps_async_result_errors_to_effects() {
    // req: axum_integration/003 req: failure/004
    async fn open_project(
        State(_multiplier): State<u32>,
        Form(_input): Form<OpenProject>,
    ) -> Result<impl IntoEffect, UiFailure> {
        Err::<(), _>(UiFailure)
    }

    let request = InteractionRequest::from(InteractionForm::for_handle(
        Handle::<()>::new(12),
        vec![("project_id".to_owned(), "21".to_owned())],
    ));
    let response = request
        .dispatch_async(
            interactions(BuildFingerprint(4))
                .with_state(2_u32)
                .on_async_result(Handle::<()>::new(12), open_project)
                .into_registry(),
        )
        .await
        .unwrap();

    assert_eq!(
        response.batch.ops,
        vec![Slot::<String>::new(3).text("try again")]
    );
}

#[test]
fn interaction_request_maps_sync_result_errors_to_effects() {
    // req: axum_integration/003 req: failure/004
    fn open_project(
        State(_multiplier): State<u32>,
        Form(_input): Form<OpenProject>,
    ) -> Result<impl IntoEffect, UiFailure> {
        Err::<(), _>(UiFailure)
    }

    let request = InteractionRequest::from(InteractionForm::for_handle(
        Handle::<()>::new(13),
        vec![("project_id".to_owned(), "21".to_owned())],
    ));
    let response = request
        .dispatch(
            interactions(BuildFingerprint(4))
                .with_state(2_u32)
                .on_result(Handle::<()>::new(13), open_project)
                .into_registry(),
        )
        .unwrap();

    assert_eq!(
        response.batch.ops,
        vec![Slot::<String>::new(3).text("try again")]
    );
}

#[test]
fn interactions_dispatch_by_checked_handle() {
    // req: ceremony/004 req: public_api/001
    let title = Slot::<String>::new(7);
    let create = Handle::<()>::new(42);
    let request = InteractionRequest::from(InteractionForm::for_handle(
        create,
        [("title".into(), "Hello".into())],
    ));

    let response = request
        .dispatch(interactions(BuildFingerprint(123)).on(create, move |form| {
            title.text(form.value("title").unwrap_or(""))
        }))
        .unwrap();

    assert_eq!(response.batch.fingerprint, BuildFingerprint(123));
    assert_eq!(response.batch.ops, vec![title.text("Hello")]);
}

#[test]
fn interactions_reject_unknown_handle_ids() {
    let request = InteractionRequest::from(InteractionForm::new(9, []));

    assert_eq!(
        request
            .dispatch(interactions(BuildFingerprint(123)))
            .unwrap_err(),
        DispatchRejection::UnknownHandle(9)
    );
}

#[test]
fn runtime_js_response_serves_embedded_runtime() {
    let response = runtime_js().into_response();

    assert_eq!(
        response.headers()[header::CONTENT_TYPE],
        HEMX_RUNTIME_CONTENT_TYPE
    );
    assert_eq!(
        response.headers()[header::CACHE_CONTROL],
        "public, max-age=31536000, immutable"
    );
    assert_eq!(
        response.headers()[header::ETAG],
        format!("\"{}\"", runtime_js_hash())
    );
    assert_eq!(
        response.headers()[header::CONTENT_LENGTH],
        runtime_js_source().len().to_string()
    );
}

// req: axum_integration/005
#[test]
fn runtime_js_path_is_content_hashed() {
    let path = runtime_js_path();

    assert!(path.starts_with("/hemx."));
    assert!(path.ends_with(".js"));
    assert!(path.contains(runtime_js_hash()));
    assert_eq!(runtime_js_script_src(), path);
    assert_eq!(runtime_js_route_path(), path);
    assert_eq!(runtime_js_hash().len(), 64);
}