use axum::{
    body::Body,
    extract::State,
    http::{StatusCode, header},
    response::{IntoResponse, Response},
};

use crate::AppState;

pub(super) fn text_asset_response(content: &'static str, content_type: &'static str) -> Response {
    Response::builder()
        .status(StatusCode::OK)
        .header(header::CONTENT_TYPE, content_type)
        .header(header::CACHE_CONTROL, "public, max-age=86400")
        .body(Body::from(content))
        .expect("text asset response")
}

pub(super) async fn robots_txt() -> Response {
    text_asset_response(
        include_str!("../../static/robots.txt"),
        "text/plain; charset=utf-8",
    )
}

pub(super) async fn llms_txt() -> Response {
    text_asset_response(
        include_str!("../../static/llms.txt"),
        "text/markdown; charset=utf-8",
    )
}

pub(super) async fn ai_txt() -> Response {
    llms_txt().await
}

pub(super) async fn i18n_js() -> Response {
    text_asset_response(
        include_str!("../../templates/i18n.js"),
        "application/javascript; charset=utf-8",
    )
}

pub(super) async fn favicon_svg() -> Response {
    Response::builder()
        .status(StatusCode::OK)
        .header(header::CONTENT_TYPE, "image/svg+xml")
        .header(header::CACHE_CONTROL, "public, max-age=86400")
        .body(Body::from(include_str!("../../static/favicon.svg")))
        .expect("favicon response")
}

/// RFC 9728 — OAuth 2.0 Protected Resource Metadata.
///
/// Advertises that this server accepts Bearer tokens in the `Authorization`
/// header.  We deliberately omit `authorization_servers` because this service
/// issues its own API keys (no external OAuth AS is involved).  MCP clients
/// that probe this endpoint will see the resource identifier and stop looking
/// for a delegated OAuth flow.
pub(super) async fn oauth_protected_resource_metadata(
    State(state): State<AppState>,
) -> impl IntoResponse {
    let body = serde_json::json!({
        "resource": state.base_url,
        "bearer_methods_supported": ["header"],
        "resource_documentation": format!("{}/dashboard", state.base_url),
    });
    (
        StatusCode::OK,
        [(header::CONTENT_TYPE, "application/json")],
        axum::Json(body),
    )
}