/**
 * CE-WP-0008 — per-session capture state round-trip.
 */

import { describe, expect, it } from "vitest";

import type { EvidenceLink } from "@shared/evidence-link";
import type { EvidenceItemId, EvidenceLinkId, SessionId } from "@shared/ids";

import {
  CAPTURE_STATE_VERSION,
  captureStateKey,
  defaultCaptureState,
  loadCaptureState,
  persistCapturePatch,
  removeCaptureState,
  saveCaptureState,
} from "./capture-persistence";

function memoryStorage(): Storage {
  const map = new Map<string, string>();
  return {
    get length() {
      return map.size;
    },
    clear: () => map.clear(),
    getItem: (k) => map.get(k) ?? null,
    key: (i) => [...map.keys()][i] ?? null,
    removeItem: (k) => void map.delete(k),
    setItem: (k, v) => void map.set(k, v),
  };
}

const SESSION = "sess_capture" as SessionId;

describe("capture-persistence", () => {
  it("uses a per-session storage key", () => {
    expect(captureStateKey(SESSION)).toBe(
      "citation-evidence:session:sess_capture:capture-state:v1",
    );
  });

  it("round-trips schema, field values, and links", () => {
    const storage = memoryStorage();
    const state = defaultCaptureState();
    const withData = {
      ...state,
      fieldValues: { summary: "Tenant owes arrears", deadline: "2026-12-15" },
      evidenceLinks: [
        {
          id: "evlink_1" as EvidenceLinkId,
          evidenceItemId: "evi_1" as EvidenceItemId,
          targetType: "form-field",
          targetId: "summary",
          relation: "supports",
          status: "candidate",
          createdAt: "2026-06-08T00:00:00.000Z",
          updatedAt: "2026-06-08T00:00:00.000Z",
        } satisfies EvidenceLink,
      ],
    };

    saveCaptureState(SESSION, withData, storage);
    const loaded = loadCaptureState(SESSION, storage);

    expect(loaded?.version).toBe(CAPTURE_STATE_VERSION);
    expect(loaded?.fieldValues).toEqual(withData.fieldValues);
    expect(loaded?.evidenceLinks).toHaveLength(1);
    expect(loaded?.formSchema.id).toBe("demo-form");
  });

  it("persistCapturePatch merges without dropping other fields", () => {
    const storage = memoryStorage();
    saveCaptureState(
      SESSION,
      {
        ...defaultCaptureState(),
        fieldValues: { amount: "1200" },
        evidenceLinks: [],
      },
      storage,
    );

    persistCapturePatch(SESSION, { fieldValues: { amount: "1500", summary: "Updated" } }, storage);

    const loaded = loadCaptureState(SESSION, storage);
    expect(loaded?.fieldValues).toEqual({ amount: "1500", summary: "Updated" });
  });

  it("removeCaptureState clears the key", () => {
    const storage = memoryStorage();
    saveCaptureState(SESSION, defaultCaptureState(), storage);
    removeCaptureState(SESSION, storage);
    expect(loadCaptureState(SESSION, storage)).toBeNull();
  });
});