/**
 * GET /api/report?cid=<cid>&cs=<cs>
 *
 * Verifies the checksum, resolves the org from the contact via the
 * Primary Contact relationship, then walks every Check-in (organizing)
 * activity for the org and assembles a per-field history of non-empty
 * values plus a summary list of the activities themselves.
 *
 * Returns ReportPayload (see types/form.ts).
 *
 * STUB MODE: if CiviCRM env vars are unset, returns synthesized history
 * shaped from the same stub used by /api/data so the report UI is
 * exercisable without a live CRM.
 */

import { NextRequest, NextResponse } from "next/server";
import { civi, verifyChecksum } from "@/lib/civicrm";
import {
  allFields,
  optionGroupIds,
  ACTIVITY_TYPE_NAME,
  ACTIVITY_STAGE_FIELD,
  FORM_CONTACT_RELATIONSHIP,
} from "@/config/form";
import type {
  ReportPayload,
  SelectOption,
  FieldHistoryEntry,
  ActivitySummary,
} from "@/types/form";

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

const STUB_PAYLOAD: ReportPayload = (() => {
  const today = new Date();
  const daysAgo = (n: number) =>
    new Date(today.getTime() - n * 24 * 3600 * 1000).toISOString();
  return {
    orgName: "Sample Co-op (stub)",
    currentStage: "Organizing",
    activities: [
      { id: 9012, date: daysAgo(3), subject: "Co-op Check-in (form submission)" },
      { id: 9008, date: daysAgo(34), subject: "Co-op Check-in (form submission)" },
      { id: 9001, date: daysAgo(62), stage: "Organizing", subject: "Stage transition (staff)" },
      { id: 8995, date: daysAgo(95), subject: "Co-op Check-in (form submission)" },
      { id: 8980, date: daysAgo(180), stage: "Inquiry", subject: "Initial check-in (staff)" },
    ],
    fieldHistory: {
      Peer_Group_Participation: [
        { activityId: 9012, date: daysAgo(3), value: "Yes" },
        { activityId: 9008, date: daysAgo(34), value: "Considering" },
        { activityId: 8995, date: daysAgo(95), value: "No" },
      ],
      Members__current_: [
        { activityId: 9012, date: daysAgo(3), value: 124 },
        { activityId: 9008, date: daysAgo(34), value: 109 },
        { activityId: 8995, date: daysAgo(95), value: 87 },
      ],
      Member_Goal_for_current_Stage: [
        { activityId: 9008, date: daysAgo(34), value: 200 },
      ],
      Internal_Startup_Assessment: [
        { activityId: 9012, date: daysAgo(3), value: "Strong" },
        { activityId: 8995, date: daysAgo(95), value: "Moderate" },
      ],
    },
    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" }],
      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" },
      ],
    },
  };
})();

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);
  }

  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 org (mirror of /api/data).
  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;

  // Org name + activity walk + option groups, in parallel.
  const civiFieldNames = Array.from(
    new Set(allFields.map((f) => f.civiField).filter((f): f is string => !!f)),
  );
  const select = [
    "id",
    "activity_date_time",
    "subject",
    ACTIVITY_STAGE_FIELD,
    ...civiFieldNames,
  ];

  const [orgRes, activityRes, options] = await Promise.all([
    civi<{ id: number; display_name: string }>("Contact", "get", {
      select: ["id", "display_name"],
      where: [["id", "=", orgId]],
    }),
    civi<Record<string, unknown> & { id: number; activity_date_time: string }>(
      "Activity",
      "get",
      {
        select,
        where: [
          ["activity_type_id:name", "=", ACTIVITY_TYPE_NAME],
          ["target_contact_id", "=", orgId],
        ],
        orderBy: { activity_date_time: "DESC", id: "DESC" },
        limit: 500,
      },
    ),
    fetchOptionGroups(),
  ]);

  const org = orgRes.values?.[0];
  if (!org) {
    return NextResponse.json({ error: "Organization not found." }, { status: 404 });
  }

  const rows = activityRes.values ?? [];

  // Activity summaries — ordered DESC already.
  const activities: ActivitySummary[] = rows.map((r) => ({
    id: r.id,
    date: r.activity_date_time,
    stage: (r[ACTIVITY_STAGE_FIELD] as string | null | undefined) ?? null,
    subject: (r.subject as string | null | undefined) ?? null,
  }));

  // Derive current stage from most recent stage-bearing activity.
  const stageRow = rows.find(
    (r) => {
      const v = r[ACTIVITY_STAGE_FIELD];
      return typeof v === "string" && v.length > 0;
    },
  );
  const currentStage =
    (typeof stageRow?.[ACTIVITY_STAGE_FIELD] === "string"
      ? (stageRow[ACTIVITY_STAGE_FIELD] as string)
      : "") || "Inquiry";

  // Per-field history. For every form-side field that has a civiField,
  // walk activities and collect non-empty values.
  const fieldHistory: Record<string, FieldHistoryEntry[]> = {};
  for (const f of allFields) {
    if (!f.civiField) continue;
    if (f.type === "readonly") continue; // readonly displays don't have history
    const entries: FieldHistoryEntry[] = [];
    for (const row of rows) {
      const v = row[f.civiField];
      if (v === null || v === undefined || v === "") continue;
      entries.push({
        activityId: row.id,
        date: row.activity_date_time,
        value: v,
      });
    }
    if (entries.length > 0) fieldHistory[f.name] = entries;
  }

  const payload: ReportPayload = {
    orgName: org.display_name,
    currentStage,
    activities,
    fieldHistory,
    options,
  };
  return NextResponse.json(payload);
}