import { writable, get } from "svelte/store";
import { listen } from "@tauri-apps/api/event";
import { invoke } from "@tauri-apps/api/core";
import { playSound, playBreakEndSound } from "../utils/sounds";
import { config } from "./config";

export interface TimerSnapshot {
  state: "running" | "paused" | "breakActive";
  currentView: "dashboard" | "breakScreen" | "settings" | "stats";
  timeRemaining: number;
  totalDuration: number;
  progress: number;
  hasHadBreak: boolean;
  secondsSinceLastBreak: number;
  prebreakWarning: boolean;
  snoozesUsed: number;
  canSnooze: boolean;
  breakTitle: string;
  breakMessage: string;
  breakProgress: number;
  breakTimeRemaining: number;
  breakTotalDuration: number;
  breakPastHalf: boolean;
  settingsModified: boolean;
  idlePaused: boolean;
  naturalBreakOccurred: boolean;
  smartBreaksEnabled: boolean;
  smartBreakThreshold: number;
  // F1: Microbreaks
  microbreakEnabled: boolean;
  microbreakActive: boolean;
  microbreakTimeRemaining: number;
  microbreakTotalDuration: number;
  microbreakCountdown: number;
  microbreakFrequency: number;
  // F3: Pomodoro
  pomodoroEnabled: boolean;
  pomodoroCyclePosition: number;
  pomodoroTotalInCycle: number;
  pomodoroIsLongBreak: boolean;
  pomodoroNextIsLong: boolean;
  // F5: Screen dimming
  screenDimActive: boolean;
  screenDimProgress: number;
  // F2: Presentation mode
  presentationModeActive: boolean;
  deferredBreakPending: boolean;
  // F10: Gamification
  isLongBreak: boolean;
}

const defaultSnapshot: TimerSnapshot = {
  state: "paused",
  currentView: "dashboard",
  timeRemaining: 1500,
  totalDuration: 1500,
  progress: 1.0,
  hasHadBreak: false,
  secondsSinceLastBreak: 0,
  prebreakWarning: false,
  snoozesUsed: 0,
  canSnooze: true,
  breakTitle: "Rest your eyes",
  breakMessage: "Look away from the screen. Stretch and relax.",
  breakProgress: 0,
  breakTimeRemaining: 0,
  breakTotalDuration: 0,
  breakPastHalf: false,
  settingsModified: false,
  idlePaused: false,
  naturalBreakOccurred: false,
  smartBreaksEnabled: true,
  smartBreakThreshold: 300,
  microbreakEnabled: false,
  microbreakActive: false,
  microbreakTimeRemaining: 0,
  microbreakTotalDuration: 0,
  microbreakCountdown: 0,
  microbreakFrequency: 1200,
  pomodoroEnabled: false,
  pomodoroCyclePosition: 0,
  pomodoroTotalInCycle: 4,
  pomodoroIsLongBreak: false,
  pomodoroNextIsLong: false,
  screenDimActive: false,
  screenDimProgress: 0,
  presentationModeActive: false,
  deferredBreakPending: false,
  isLongBreak: false,
};

export const timer = writable<TimerSnapshot>(defaultSnapshot);

// Track the current view separately so UI can switch views optimistically
export const currentView = writable<
  "dashboard" | "breakScreen" | "settings" | "stats"
>("dashboard");

let initialized = false;

export async function initTimerStore() {
  if (initialized) return;
  initialized = true;

  // Get initial state
  try {
    const snapshot = await invoke<TimerSnapshot>("get_timer_state");
    timer.set(snapshot);
    currentView.set(snapshot.currentView);
  } catch (e) {
    console.error("Failed to get initial timer state:", e);
  }

  // Listen for tick events
  await listen<TimerSnapshot>("timer-tick", (event) => {
    timer.set(event.payload);
    // Sync view from backend (backend is authoritative for break transitions)
    currentView.set(event.payload.currentView);
  });

  // Listen for pre-break warning
  await listen("prebreak-warning", () => {
    const cfg = get(config);
    if (cfg.sound_enabled) {
      playSound(cfg.sound_preset as any, cfg.sound_volume * 0.6);
    }
  });

  // Listen for break started
  await listen("break-started", () => {
    currentView.set("breakScreen");
    const cfg = get(config);
    if (cfg.sound_enabled) {
      playSound(cfg.sound_preset as any, cfg.sound_volume);
    }
  });

  // Listen for break ended
  await listen("break-ended", () => {
    currentView.set("dashboard");
    const cfg = get(config);
    if (cfg.sound_enabled) {
      playBreakEndSound(cfg.sound_preset as any, cfg.sound_volume);
    }
  });

  // Listen for natural break detected
  await listen<number>("natural-break-detected", (event) => {
    const cfg = get(config);
    if (cfg.sound_enabled) {
      playSound(cfg.sound_preset as any, cfg.sound_volume * 0.5);
    }
  });

  // F1: Microbreak events
  await listen("microbreak-started", () => {
    const cfg = get(config);
    if (cfg.microbreak_sound_enabled && cfg.sound_enabled) {
      playSound(cfg.sound_preset as any, cfg.sound_volume * 0.4);
    }
  });

  await listen("microbreak-ended", () => {
    const cfg = get(config);
    if (cfg.microbreak_sound_enabled && cfg.sound_enabled) {
      playBreakEndSound(cfg.sound_preset as any, cfg.sound_volume * 0.3);
    }
  });

  // F10: Milestone and daily goal events
  await listen<{ streak: number }>("milestone-reached", (event) => {
    milestoneEvent.set(event.payload.streak);
    setTimeout(() => milestoneEvent.set(null), 4000);
  });

  await listen("daily-goal-met", () => {
    dailyGoalEvent.set(true);
    setTimeout(() => dailyGoalEvent.set(false), 4000);
  });

  // F2: Break deferred
  await listen("break-deferred", () => {
    // Dashboard will show deferred status from snapshot
  });
}

// F10: Gamification event stores
export const milestoneEvent = writable<number | null>(null);
export const dailyGoalEvent = writable<boolean>(false);

// Helper: format seconds as MM:SS
export function formatTime(secs: number): string {
  const m = Math.floor(secs / 60);
  const s = secs % 60;
  return `${String(m).padStart(2, "0")}:${String(s).padStart(2, "0")}`;
}

// Helper: format "X ago" string
export function formatDurationAgo(secs: number): string {
  if (secs < 60) return `${secs} sec ago`;
  const m = Math.floor(secs / 60);
  if (m < 60) return m === 1 ? "1 min ago" : `${m} min ago`;
  const h = Math.floor(secs / 3600);
  return h === 1 ? "1 hr ago" : `${h} hrs ago`;
}