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 VALID_STATUSES = [
  "contracts_received",
  "under_revision",
  "done",
  "validated",
  "canceled",
] as const;

export const handler: Handlers<null, AuthenticatedState> = {
  // GET /mobilites — list all, optional ?numEtud filter
  async GET(request) {
    try {
      const url = new URL(request.url);
      const numEtudParam = url.searchParams.get("numEtud");

      let query = db.select().from(mobilites).$dynamic();

      if (numEtudParam) {
        const numEtud = parseInt(numEtudParam);
        if (isNaN(numEtud)) {
          return new Response("Paramètre numEtud invalide", { status: 400 });
        }
        query = query.where(eq(mobilites.numEtud, numEtud));
      }

      const result = await query;

      return new Response(JSON.stringify(result), {
        status: 200,
        headers: { "Content-Type": "application/json" },
      });
    } catch (error) {
      console.error("Error fetching mobilites:", error);
      return new Response("Failed to fetch data", { status: 500 });
    }
  },

  // POST /mobilites — create mobility
  async POST(
    request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    const isEmployee =
      context.state.session.eduPersonPrimaryAffiliation === "employee";

    try {
      const body = await request.json();
      const { numEtud, duree, ecole, pays, status, idStage } = body;

      // Students can only create mobilites for themselves
      if (!isEmployee && numEtud !== undefined) {
        // Students cannot set idStage or status
        if (idStage || (status && status !== "contracts_received")) {
          return new Response(null, { status: 403 });
        }
      }

      if (!numEtud || duree === undefined) {
        return new Response(
          JSON.stringify({ error: "Champs requis: numEtud, duree" }),
          { status: 400, headers: { "content-type": "application/json" } },
        );
      }

      if (!Number.isInteger(duree) || duree < 1) {
        return new Response(
          JSON.stringify({ error: "duree doit être un entier >= 1" }),
          { status: 400, headers: { "content-type": "application/json" } },
        );
      }

      if (
        status !== undefined &&
        !VALID_STATUSES.includes(status)
      ) {
        return new Response(
          JSON.stringify({
            error: `status invalide, valeurs: ${VALID_STATUSES.join(", ")}`,
          }),
          { status: 400, headers: { "content-type": "application/json" } },
        );
      }

      // Stage-linked mobilities are always validated
      const effectiveStatus = idStage
        ? "validated"
        : (status ?? "contracts_received");

      const [created] = await db
        .insert(mobilites)
        .values({
          numEtud,
          duree,
          ecole: ecole ?? null,
          pays: pays ?? null,
          status: effectiveStatus,
          idStage: idStage ?? null,
        })
        .returning();

      return new Response(JSON.stringify(created), {
        status: 201,
        headers: { "content-type": "application/json" },
      });
    } catch (error) {
      console.error("Error creating mobilite:", error);
      return new Response("Failed to create mobilite", { status: 500 });
    }
  },
};