import { FreshContext, Handlers } from "$fresh/server.ts";
import { db } from "$root/databases/db.ts";
import { mobilites } from "$root/databases/schema.ts";
import { AuthenticatedState } from "$root/defaults/interfaces.ts";
import { eq } from "npm:drizzle-orm@0.45.2";

const CONTRACTS_DIR = "uploads/contracts";

export const handler: Handlers<null, AuthenticatedState> = {
  // GET /mobilites/:idMob/contrat — download contract PDF
  async GET(
    _request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    const idMob = Number(context.params.idMob);
    if (isNaN(idMob)) {
      return new Response("Paramètre idMob invalide", { status: 400 });
    }

    const row = await db
      .select({ contratMob: mobilites.contratMob })
      .from(mobilites)
      .where(eq(mobilites.id, idMob))
      .then((rows) => rows[0] ?? null);

    if (!row) {
      return new Response(
        JSON.stringify({ error: "Mobilité introuvable" }),
        { status: 404, headers: { "content-type": "application/json" } },
      );
    }

    if (!row.contratMob) {
      return new Response(
        JSON.stringify({ error: "Aucun contrat pour cette mobilité" }),
        { status: 404, headers: { "content-type": "application/json" } },
      );
    }

    try {
      const file = await Deno.readFile(`${CONTRACTS_DIR}/${row.contratMob}`);
      return new Response(file, {
        headers: {
          "Content-Type": "application/pdf",
          "Content-Disposition": `inline; filename="${row.contratMob}"`,
        },
      });
    } catch {
      return new Response(
        JSON.stringify({ error: "Fichier contrat introuvable" }),
        { status: 404, headers: { "content-type": "application/json" } },
      );
    }
  },

  // POST /mobilites/:idMob/contrat — upload contract PDF
  async POST(
    request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    const idMob = Number(context.params.idMob);
    if (isNaN(idMob)) {
      return new Response("Paramètre idMob invalide", { status: 400 });
    }

    // Check mobility exists
    const row = await db
      .select({ id: mobilites.id })
      .from(mobilites)
      .where(eq(mobilites.id, idMob))
      .then((rows) => rows[0] ?? null);

    if (!row) {
      return new Response(
        JSON.stringify({ error: "Mobilité introuvable" }),
        { status: 404, headers: { "content-type": "application/json" } },
      );
    }

    const formData = await request.formData();
    const file = formData.get("contrat");

    if (!file || !(file instanceof File)) {
      return new Response(
        JSON.stringify({ error: "Fichier 'contrat' requis (PDF)" }),
        { status: 400, headers: { "content-type": "application/json" } },
      );
    }

    if (file.type !== "application/pdf") {
      return new Response(
        JSON.stringify({ error: "Le fichier doit être un PDF" }),
        { status: 400, headers: { "content-type": "application/json" } },
      );
    }

    const filename = `mob_${idMob}.pdf`;
    await Deno.mkdir(CONTRACTS_DIR, { recursive: true });
    await Deno.writeFile(
      `${CONTRACTS_DIR}/${filename}`,
      new Uint8Array(await file.arrayBuffer()),
    );

    const [updated] = await db
      .update(mobilites)
      .set({ contratMob: filename })
      .where(eq(mobilites.id, idMob))
      .returning();

    return new Response(JSON.stringify(updated), {
      status: 200,
      headers: { "content-type": "application/json" },
    });
  },

  // DELETE /mobilites/:idMob/contrat — remove contract (employee only)
  async DELETE(
    _request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    if (context.state.session.eduPersonPrimaryAffiliation !== "employee") {
      return new Response(null, { status: 403 });
    }

    const idMob = Number(context.params.idMob);
    if (isNaN(idMob)) {
      return new Response("Paramètre idMob invalide", { status: 400 });
    }

    const row = await db
      .select({ contratMob: mobilites.contratMob })
      .from(mobilites)
      .where(eq(mobilites.id, idMob))
      .then((rows) => rows[0] ?? null);

    if (!row) {
      return new Response(
        JSON.stringify({ error: "Mobilité introuvable" }),
        { status: 404, headers: { "content-type": "application/json" } },
      );
    }

    if (row.contratMob) {
      try {
        await Deno.remove(`${CONTRACTS_DIR}/${row.contratMob}`);
      } catch { /* file may not exist */ }
    }

    await db
      .update(mobilites)
      .set({ contratMob: null })
      .where(eq(mobilites.id, idMob));

    return new Response(null, { status: 204 });
  },
};