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

const NOT_FOUND = () =>
  new Response(
    JSON.stringify({ error: "Ajustement introuvable" }),
    { status: 404, headers: { "content-type": "application/json" } },
  );

const FORBIDDEN = () => new Response(null, { status: 403 });

export const handler: Handlers<null, AuthenticatedState> = {
  // #50 GET /ajustements/{numEtud}/{idUE}
  async GET(
    _request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    if (!isEmployee(context.state.session)) {
      return FORBIDDEN();
    }

    const numEtud = Number(context.params.numEtud);
    const idUE = Number(context.params.idUE);

    if (isNaN(numEtud) || isNaN(idUE)) {
      return new Response("Paramètres invalides", { status: 400 });
    }

    const ajustement = await db
      .select()
      .from(ajustements)
      .where(and(eq(ajustements.numEtud, numEtud), eq(ajustements.idUE, idUE)))
      .then((rows) => rows[0] ?? null);

    if (!ajustement) return NOT_FOUND();

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

  // #51 PUT /ajustements/{numEtud}/{idUE}
  async PUT(
    request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    if (!isEmployee(context.state.session)) {
      return FORBIDDEN();
    }

    const numEtud = Number(context.params.numEtud);
    const idUE = Number(context.params.idUE);

    if (isNaN(numEtud) || isNaN(idUE)) {
      return new Response("Paramètres invalides", { status: 400 });
    }

    const body: { valeur: number; malus?: number } = await request.json();

    if (body.valeur === undefined) {
      return new Response(JSON.stringify({ error: "Champ requis: valeur" }), {
        status: 400,
        headers: { "content-type": "application/json" },
      });
    }

    if (
      body.malus !== undefined &&
      (!Number.isInteger(body.malus) || body.malus < 0)
    ) {
      return new Response(
        JSON.stringify({ error: "malus doit être un entier >= 0" }),
        { status: 400, headers: { "content-type": "application/json" } },
      );
    }

    const set: { valeur: number; malus?: number } = { valeur: body.valeur };
    if (body.malus !== undefined) {
      set.malus = body.malus;
    }

    const [updated] = await db
      .update(ajustements)
      .set(set)
      .where(and(eq(ajustements.numEtud, numEtud), eq(ajustements.idUE, idUE)))
      .returning();

    if (!updated) return NOT_FOUND();

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

  // #52 DELETE /ajustements/{numEtud}/{idUE}
  async DELETE(
    _request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    if (!isEmployee(context.state.session)) {
      return FORBIDDEN();
    }

    const numEtud = Number(context.params.numEtud);
    const idUE = Number(context.params.idUE);

    if (isNaN(numEtud) || isNaN(idUE)) {
      return new Response("Paramètres invalides", { status: 400 });
    }

    const [deleted] = await db
      .delete(ajustements)
      .where(and(eq(ajustements.numEtud, numEtud), eq(ajustements.idUE, idUE)))
      .returning();

    if (!deleted) return NOT_FOUND();

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