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

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

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

export const handler: Handlers<null, AuthenticatedState> = {
  // #10 GET /students/{numEtud}
  async GET(
    _request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    if (context.state.session.eduPersonPrimaryAffiliation !== "employee") {
      return FORBIDDEN();
    }

    const numEtud = Number(context.params.numEtud);
    const student = await db
      .select()
      .from(students)
      .where(eq(students.numEtud, numEtud))
      .then((rows) => rows[0] ?? null);

    if (!student) return NOT_FOUND();

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

  // #11 PUT /students/{numEtud}
  async PUT(
    request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    if (context.state.session.eduPersonPrimaryAffiliation !== "employee") {
      return FORBIDDEN();
    }

    const numEtud = Number(context.params.numEtud);
    const body: { nom?: string; prenom?: string; idPromo?: string } =
      await request.json();

    const set: { nom?: string; prenom?: string; idPromo?: string } = {};
    if (body.nom !== undefined) set.nom = body.nom;
    if (body.prenom !== undefined) set.prenom = body.prenom;
    if (body.idPromo !== undefined) set.idPromo = body.idPromo;

    if (Object.keys(set).length === 0) {
      return new Response(
        JSON.stringify({ error: "Au moins un champ requis" }),
        { status: 400, headers: { "content-type": "application/json" } },
      );
    }

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

    if (!updated) return NOT_FOUND();

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

  // #12 DELETE /students/{numEtud}
  // Cascade: deletes notes, ajustements, mobilites, stages for this student.
  async DELETE(
    _request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    if (context.state.session.eduPersonPrimaryAffiliation !== "employee") {
      return FORBIDDEN();
    }

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

    const student = await db
      .select()
      .from(students)
      .where(eq(students.numEtud, numEtud))
      .then((r) => r[0] ?? null);

    if (!student) return NOT_FOUND();

    await db.transaction(async (tx) => {
      await tx.delete(notes).where(eq(notes.numEtud, numEtud));
      await tx.delete(ajustements).where(eq(ajustements.numEtud, numEtud));
      await tx.delete(mobilites).where(eq(mobilites.numEtud, numEtud));
      await tx.delete(stages).where(eq(stages.numEtud, numEtud));
      await tx.delete(students).where(eq(students.numEtud, numEtud));
    });

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