/**
 * GET /api/data?cid=<cid>&cs=<cs>
 *
 * Verifies the checksum, resolves the org from the contact via the
 * Primary Contact relationship, reads the org's Framework Stage
 * (`Food_Co_op_Organizing.Stage` on the Organization contact), and walks
 * past `Check-in (organizing)` activities for per-field most-recent prefill.
 *
 * Also fetches the OptionValue rows for any option_group_ids referenced by
 * the form (so radio/select/multiselect fields render with real CRM-defined
 * options) and returns them in `payload.options`.
 *
 * Returns FormDataPayload (see types/form.ts).
 *
 * STUB MODE: if CiviCRM env vars are unset, returns mock data + a small set
 * of mock options so the UI is exercisable without a live CRM.
 */

import { NextRequest, NextResponse } from "next/server";
import { civi, verifyChecksum } from "@/lib/civicrm";
import { loadPrefill } from "@/lib/prefill";
import { allFields, optionGroupIds, ACTIVITY_TYPE_NAME, FORM_CONTACT_RELATIONSHIP } from "@/config/form";
import type { FormDataPayload, SelectOption } from "@/types/form";

const STUB_PAYLOAD: FormDataPayload = {
  orgName: "Sample Co-op (stub)",
  currentStage: "Organizing",
  prefill: {
    Peer_Group_Participation: "Yes",
    Members__current_: 87,
    Total_members_at_opening: null,
    Projected_Year_1_Sales: 2400000,
    Projected_Year_2_Sales: 2950000,
    Total_cost_of_project: 4200000,
    Vision: "2024-09-15",
    Business_Concept: "2024-12-02",
  },
  options: {
    140: [{ value: "Yes", label: "Yes" }, { value: "No", label: "No" }, { value: "Considering", label: "Considering" }],
    132: [{ value: "Strong", label: "Strong" }, { value: "Moderate", label: "Moderate" }, { value: "Needs Work", label: "Needs work" }],
    141: [{ value: "Yes", label: "Yes" }, { value: "No", label: "No" }],
    142: [{ value: "Yes", label: "Yes" }, { value: "No", label: "No" }],
    133: [{ value: "Viable", label: "Viable" }, { value: "Marginal", label: "Marginal" }, { value: "Not viable", label: "Not viable" }],
    134: [{ value: "Member equity", label: "Member equity" }, { value: "Member loans", label: "Member loans" }, { value: "Bank debt", label: "Bank debt" }, { value: "Grants", label: "Grants" }],
    139: [{ value: "Yes", label: "Yes" }, { value: "No", label: "No" }],
    135: [{ value: "Co-op", label: "Co-op grocery" }, { value: "Conventional", label: "Conventional grocery" }, { value: "Other", label: "Other" }],
    136: [{ value: "Member", label: "Member" }, { value: "Considering", label: "Considering" }, { value: "Not a member", label: "Not a member" }],
    137: [{ value: "Member", label: "Member" }, { value: "Considering", label: "Considering" }, { value: "Not a member", label: "Not a member" }],
    138: [{ value: "UNFI", label: "UNFI" }, { value: "KeHE", label: "KeHE" }, { value: "Other", label: "Other" }, { value: "None", label: "None" }],
    143: [{ value: "Northeast", label: "Northeast" }, { value: "Mid-Atlantic", label: "Mid-Atlantic" }, { value: "Midwest", label: "Midwest" }, { value: "South", label: "South" }, { value: "West", label: "West" }],
    75: [
      { value: "Inquiry", label: "Inquiry" },
      { value: "Organizing", label: "Stage 1 — Convene & Prepare" },
      { value: "Feasibility", label: "Stage 2 — Grow & Plan" },
      { value: "Business feasibility", label: "Stage 3 — Connect & Gather" },
      { value: "Store Implementation", label: "Stage 4 — Excite & Build" },
      { value: "Stabilize newly opened co-op", label: "Stage 5 — Fulfill & Stabilize" },
    ],
  },
};

function isStubMode(): boolean {
  return !(
    process.env.CIVI_BASE_URL &&
    process.env.CIVI_API_KEY &&
    process.env.CIVI_SITE_KEY
  );
}

interface OptionValueRow {
  value: string;
  label: string;
  option_group_id: number;
  is_active: boolean;
}

async function fetchOptionGroups(): Promise<Record<number, SelectOption[]>> {
  if (optionGroupIds.length === 0) return {};
  const res = await civi<OptionValueRow>("OptionValue", "get", {
    select: ["value", "label", "option_group_id", "is_active"],
    where: [
      ["option_group_id", "IN", optionGroupIds],
      ["is_active", "=", true],
    ],
    orderBy: { weight: "ASC" },
    limit: 500,
  });
  const out: Record<number, SelectOption[]> = {};
  for (const row of res.values ?? []) {
    if (!out[row.option_group_id]) out[row.option_group_id] = [];
    out[row.option_group_id].push({ value: row.value, label: row.label });
  }
  return out;
}

export async function GET(req: NextRequest) {
  const url = new URL(req.url);
  const cid = url.searchParams.get("cid");
  const cs = url.searchParams.get("cs");

  if (!cid || !cs) {
    return NextResponse.json(
      { error: "Missing cid or cs parameter." },
      { status: 400 },
    );
  }

  if (isStubMode()) {
    return NextResponse.json(STUB_PAYLOAD);
  }

  // Verify checksum first.
  const ok = await verifyChecksum(cid, cs);
  if (!ok) {
    return NextResponse.json(
      { error: "Link is invalid or has expired. Please request a fresh one." },
      { status: 401 },
    );
  }

  // Resolve the org from the contact's "Primary Contact" relationship.
  // The relationship is Individual (A) → Organization (B); fetch contact_id_b.
  const relRes = await civi<{ contact_id_b: number }>("Relationship", "get", {
    select: ["contact_id_b"],
    where: [
      ["contact_id_a", "=", Number(cid)],
      ["relationship_type_id.name_a_b", "=", FORM_CONTACT_RELATIONSHIP],
      ["is_active", "=", true],
    ],
    limit: 2,
  });
  const orgs = relRes.values ?? [];
  if (orgs.length === 0) {
    return NextResponse.json(
      { error: `No active "${FORM_CONTACT_RELATIONSHIP}" relationship found for your contact.` },
      { status: 404 },
    );
  }
  if (orgs.length > 1) {
    return NextResponse.json(
      { error: `Your contact has multiple active "${FORM_CONTACT_RELATIONSHIP}" relationships; staff must resolve before this link will work.` },
      { status: 409 },
    );
  }
  const orgId = orgs[0].contact_id_b;

  // Fetch org name + Framework Stage (org-side, on the organization contact).
  const orgRes = await civi<{
    id: number;
    display_name: string;
    "Food_Co_op_Organizing.Stage": string | null;
  }>("Contact", "get", {
    select: ["id", "display_name", "Food_Co_op_Organizing.Stage"],
    where: [["id", "=", orgId]],
  });
  const org = orgRes.values?.[0];
  if (!org) {
    return NextResponse.json({ error: "Organization not found." }, { status: 404 });
  }
  const currentStage = org["Food_Co_op_Organizing.Stage"] ?? "";

  // Per-field-most-recent prefill across past Check-in activities, plus
  // option-group fetch — kicked off in parallel.
  const [{ values: prefill }, options] = await Promise.all([
    loadPrefill(orgId, allFields, ACTIVITY_TYPE_NAME),
    fetchOptionGroups(),
  ]);

  const payload: FormDataPayload = {
    orgName: org.display_name,
    currentStage: typeof currentStage === "string" ? currentStage : "",
    prefill,
    options,
  };
  return NextResponse.json(payload);
}