/**
 * Day 4 — local, device-only beta feedback.
 *
 * Lets a beta student tell the builder what confused them or what broke, stored
 * only in localStorage. No backend, no external service. Deliberately collects
 * NO contact/personal data: no name, email, phone, school, or location fields.
 * The message is capped and trimmed; empty messages are rejected.
 */

import { getBetaSessionId, trackBetaEvent } from "./betaAnalytics";

export type BetaFeedbackKind =
  | "helped_understand"
  | "still_confusing"
  | "wrong_or_doubtful"
  | "too_long"
  | "need_more_examples"
  | "class_confusing"
  | "bug"
  | "content_issue"
  | "ui_issue"
  | "too_hard"
  | "too_easy"
  | "liked"
  | "other";

export type BetaFeedbackRating = 1 | 2 | 3 | 4 | 5;

export type BetaFeedbackDevice = {
  viewportWidth?: number;
  viewportHeight?: number;
  userAgent?: string;
};

export type BetaFeedbackItem = {
  id: string;
  createdAt: string;
  sessionId: string;
  kind: BetaFeedbackKind;
  rating?: BetaFeedbackRating;
  message: string;
  route: string;
  subject?: string;
  chapterTitle?: string;
  missionTitle?: string;
  stepLabel?: string;
  device?: BetaFeedbackDevice;
  status: "new" | "reviewed";
};

export type BetaFeedbackContext = {
  kind: BetaFeedbackKind;
  rating?: BetaFeedbackRating;
  message: string;
  route?: string;
  subject?: string;
  chapterTitle?: string;
  missionTitle?: string;
  stepLabel?: string;
  includeDevice?: boolean;
};

export type BetaFeedbackSubmitResult =
  | { ok: true; item: BetaFeedbackItem }
  | { ok: false; error: "empty_message" | "storage_unavailable" };

export type BetaFeedbackSummary = {
  total: number;
  newCount: number;
  reviewedCount: number;
  byKind: Array<{ kind: BetaFeedbackKind; count: number }>;
  bugCount: number;
  lastAt: string | null;
};

export const BETA_FEEDBACK_STORAGE_KEY = "docdoe:beta-feedback";

export const MAX_FEEDBACK_MESSAGE_LENGTH = 500;
const MAX_STORED_FEEDBACK = 200;

export const BETA_FEEDBACK_KIND_LABELS: Record<BetaFeedbackKind, string> = {
  helped_understand: "This helped me understand",
  still_confusing: "Still confusing",
  wrong_or_doubtful: "Wrong or doubtful answer",
  too_long: "Too long",
  need_more_examples: "Need more examples",
  class_confusing: "Class was confusing",
  bug: "Something broke (bug)",
  content_issue: "Content looks wrong",
  ui_issue: "Layout / UI problem",
  too_hard: "Too hard",
  too_easy: "Too easy",
  liked: "I liked this",
  other: "Other",
};

function hasStorage(): boolean {
  return typeof window !== "undefined" && typeof window.localStorage !== "undefined";
}

function randomId(): string {
  try {
    if (typeof crypto !== "undefined" && typeof crypto.randomUUID === "function") return crypto.randomUUID();
  } catch {
    // fall through
  }
  return `${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 10)}`;
}

function currentRoute(): string {
  if (typeof window === "undefined") return "";
  try {
    return window.location?.pathname ?? "";
  } catch {
    return "";
  }
}

function isFeedbackLike(value: unknown): value is BetaFeedbackItem {
  if (!value || typeof value !== "object") return false;
  const item = value as Record<string, unknown>;
  return typeof item.id === "string" && typeof item.kind === "string" && typeof item.message === "string";
}

export function loadBetaFeedback(): BetaFeedbackItem[] {
  if (!hasStorage()) return [];
  try {
    const raw = window.localStorage.getItem(BETA_FEEDBACK_STORAGE_KEY);
    if (!raw) return [];
    const parsed = JSON.parse(raw);
    if (!Array.isArray(parsed)) return [];
    return parsed.filter(isFeedbackLike);
  } catch {
    return [];
  }
}

export function saveBetaFeedback(items: BetaFeedbackItem[]): void {
  if (!hasStorage()) return;
  try {
    window.localStorage.setItem(BETA_FEEDBACK_STORAGE_KEY, JSON.stringify(items.slice(-MAX_STORED_FEEDBACK)));
  } catch {
    // best-effort
  }
}

function minimalDevice(): BetaFeedbackDevice | undefined {
  if (typeof window === "undefined") return undefined;
  try {
    return {
      viewportWidth: window.innerWidth,
      viewportHeight: window.innerHeight,
      // Coarse UA only; no fingerprinting, no PII.
      userAgent: (navigator?.userAgent ?? "").slice(0, 180),
    };
  } catch {
    return undefined;
  }
}

/**
 * Validate + store one feedback item, and record analytics events
 * (feedback_submitted, plus bug_report_submitted when kind === "bug").
 */
export function submitBetaFeedback(context: BetaFeedbackContext): BetaFeedbackSubmitResult {
  const message = (context.message ?? "").trim().slice(0, MAX_FEEDBACK_MESSAGE_LENGTH);
  if (!message) return { ok: false, error: "empty_message" };
  if (!hasStorage()) return { ok: false, error: "storage_unavailable" };

  const item: BetaFeedbackItem = {
    id: randomId(),
    createdAt: new Date().toISOString(),
    sessionId: getBetaSessionId(),
    kind: context.kind,
    rating: context.rating,
    message,
    route: context.route ?? currentRoute(),
    subject: context.subject,
    chapterTitle: context.chapterTitle,
    missionTitle: context.missionTitle,
    stepLabel: context.stepLabel,
    device: context.includeDevice === false ? undefined : minimalDevice(),
    status: "new",
  };

  const items = [...loadBetaFeedback(), item];
  saveBetaFeedback(items);

  const analyticsContext = {
    subject: context.subject,
    chapterTitle: context.chapterTitle,
    missionTitle: context.missionTitle,
    stepLabel: context.stepLabel,
    route: context.route,
  };
  trackBetaEvent({ name: "feedback_submitted", metadata: { kind: item.kind, rating: item.rating ?? null }, ...analyticsContext });
  if (item.kind === "bug") {
    trackBetaEvent({ name: "bug_report_submitted", metadata: { rating: item.rating ?? null }, ...analyticsContext });
  }
  if (item.kind === "still_confusing") {
    trackBetaEvent({ name: "confusing_answer_reported", metadata: { kind: item.kind }, ...analyticsContext });
  }
  if (item.kind === "wrong_or_doubtful") {
    trackBetaEvent({ name: "wrong_answer_reported", metadata: { kind: item.kind }, ...analyticsContext });
  }

  return { ok: true, item };
}

export function markBetaFeedbackReviewed(id: string): BetaFeedbackItem[] {
  const items = loadBetaFeedback().map((item) => (item.id === id ? { ...item, status: "reviewed" as const } : item));
  saveBetaFeedback(items);
  return items;
}

export function clearBetaFeedback(): void {
  if (!hasStorage()) return;
  try {
    window.localStorage.removeItem(BETA_FEEDBACK_STORAGE_KEY);
  } catch {
    // ignore
  }
}

export function getBetaFeedbackSummary(items: BetaFeedbackItem[] = loadBetaFeedback()): BetaFeedbackSummary {
  const byKind = new Map<BetaFeedbackKind, number>();
  for (const item of items) byKind.set(item.kind, (byKind.get(item.kind) ?? 0) + 1);

  return {
    total: items.length,
    newCount: items.filter((item) => item.status === "new").length,
    reviewedCount: items.filter((item) => item.status === "reviewed").length,
    byKind: Array.from(byKind.entries()).map(([kind, count]) => ({ kind, count })),
    bugCount: items.filter((item) => item.kind === "bug").length,
    lastAt: items.length > 0 ? items[items.length - 1].createdAt : null,
  };
}