package sola.documentation.boundary;

import jakarta.ws.rs.*;
import jakarta.ws.rs.core.Response;
import org.eclipse.microprofile.config.inject.ConfigProperty;
import sola.documentation.Requirement;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.InvalidPathException;
import java.util.Locale;
import static sola.documentation.Requirement.Rn.*;

/** Optional public projection of a reviewed build; owner APIs retain their own authentication. */
@Path("/")
@jakarta.enterprise.context.ApplicationScoped
public class DocumentationResource {
    @ConfigProperty(name="sola.documentation.root", defaultValue="/app/documentation")
    String directory;

    /// @requirement R1.1 serve the published homepage without a login
    @GET @Requirement(R1_1)
    public Response home() { return serve("index.html"); }

    /// @requirement R1.2 serve a published artifact with its media type
    /// @requirement R2.1 refuse escape paths and unpublished files
    @GET @Path("docs/{path: .+}") @Requirement({R1_2, R2_1})
    public Response artifact(@PathParam("path") String path) { return serve(path); }

    /// @requirement R3.1 identify the documentation build and its evidence
    @GET @Path("api/docs/manifest") @Requirement(R3_1)
    public Response manifest() { return serve("manifest.json"); }

    private Response serve(String requested) {
        try {
            if (requested == null || requested.indexOf('\\') >= 0 || requested.indexOf('\0') >= 0)
                throw new NotFoundException();
            java.nio.file.Path root = java.nio.file.Path.of(directory).toRealPath();
            java.nio.file.Path candidate = root.resolve(requested).normalize();
            if (!candidate.startsWith(root) || !Files.isRegularFile(candidate)
                    || !candidate.toRealPath().startsWith(root)) throw new NotFoundException();
            String media = mediaType(candidate.getFileName().toString());
            if (media == null) throw new NotFoundException();
            return Response.ok(Files.readAllBytes(candidate), media)
                    .header("X-Content-Type-Options", "nosniff")
                    .header("Content-Security-Policy", "default-src 'self'; style-src 'self' 'unsafe-inline'; object-src 'none'; frame-ancestors 'none'")
                    .build();
        } catch (IOException | InvalidPathException e) {
            throw new NotFoundException();
        }
    }

    private static String mediaType(String filename) {
        String name = filename.toLowerCase(Locale.ROOT);
        if (name.endsWith(".html")) return "text/html; charset=utf-8";
        if (name.endsWith(".pdf")) return "application/pdf";
        if (name.endsWith(".json")) return "application/json";
        if (name.endsWith(".md") || name.endsWith(".java")) return "text/plain; charset=utf-8";
        return null;
    }
}