import { computed, onUnmounted, ref } from "vue";

const pad2 = (value) => value.toString().padStart(2, "0");

export function useWashProgress(options) {
  const {
    storageKey = "mywash_progress_v6",
    expirationMs = 2 * 60 * 60 * 1000,
    currentStep,
    washInProgress,
    washLaneId,
    washStartTime,
    licensePlateInput,
    vehicleTypeSelect,
    radioWashType,
    radioLaneOption,
    customerNumberInput,
    answers,
    completedTasks,
    nearestDepartmentId,
    forceNearestDepartmentEvaluationId,
    isForcingNearestDepartment,
    applyRestoredState,
  } = options;

  const isRestoring = ref(true);
  const isDestroying = ref(false);
  const isDestroyingManual = ref(false);
  const completedDurationMs = ref(null);
  const now = ref(Date.now());

  let timerInterval = null;
  let isDestroyingGlobal = false;
  let beforeUnloadHandler = null;

  const timeSinceWashStart = computed(() => {
    if (washInProgress.value && washStartTime.value) {
      return now.value - washStartTime.value;
    }

    return 0;
  });

  const formattedElapsed = computed(() => {
    const totalSeconds = Math.floor(timeSinceWashStart.value / 1000);
    const minutes = Math.floor(totalSeconds / 60);
    const seconds = totalSeconds % 60;

    if (minutes < 0 || seconds < 0) {
      return "00:00";
    }

    return `${pad2(minutes)}:${pad2(seconds)}`;
  });

  const loadProgress = () => {
    try {
      const raw = localStorage.getItem(storageKey);
      if (!raw) {
        return null;
      }

      return JSON.parse(raw);
    } catch (error) {
      console.warn("Failed to load wash progress:", error);
      return null;
    }
  };

  const clearProgress = () => {
    try {
      localStorage.removeItem(storageKey);
    } catch {}
  };

  const saveProgress = (trigger = "manual") => {
    if (isRestoring.value) {
      return;
    }

    if (isDestroying.value || isDestroyingManual.value || isDestroyingGlobal) {
      if (trigger !== "beforeunload") {
        return;
      }
    }

    if (
      washInProgress.value
      && currentStep.value === 0
      && trigger !== "onStartWash"
      && trigger !== "onCloseCompleted"
    ) {
      return;
    }

    if (!washInProgress.value && Number(currentStep.value) === 5) {
      clearProgress();
      return;
    }

    try {
      const payload = {
        washInProgress: washInProgress.value,
        washLaneId: washLaneId.value,
        washStartTime: washStartTime.value,
        currentStep: currentStep.value,
        licensePlateInput: licensePlateInput.value,
        vehicleTypeSelect: vehicleTypeSelect.value,
        radioWashType: radioWashType.value,
        radioLaneOption: radioLaneOption.value,
        customerNumberInput: customerNumberInput.value,
        answers: answers.value,
        completedTasks: completedTasks.value,
        nearestDepartmentId: nearestDepartmentId(),
        forceNearestDepartmentEvaluationId: forceNearestDepartmentEvaluationId.value,
        savedAt: Date.now(),
        isForcingNearestDepartment: isForcingNearestDepartment.value,
      };

      localStorage.setItem(storageKey, JSON.stringify(payload));
    } catch (error) {
      console.warn("Failed to save wash progress:", error);
    }
  };

  const startElapsedTimer = () => {
    if (timerInterval) {
      clearInterval(timerInterval);
    }

    timerInterval = setInterval(() => {
      now.value = Date.now();
      if (washInProgress.value) {
        saveProgress("timer");
      }
    }, 1000);
  };

  const stopElapsedTimer = () => {
    if (timerInterval) {
      clearInterval(timerInterval);
      timerInterval = null;
    }
  };

  const markDestroying = () => {
    isDestroyingGlobal = true;
    isDestroyingManual.value = true;
    isDestroying.value = true;
  };

  const restoreProgress = () => {
    const savedProgress = loadProgress();
    if (!savedProgress) {
      isRestoring.value = false;
      return null;
    }

    const timeDiff = Date.now() - (savedProgress.savedAt || 0);
    if (timeDiff >= expirationMs) {
      clearProgress();
      isRestoring.value = false;
      return null;
    }

    applyRestoredState(savedProgress);

    if (washInProgress.value) {
      startElapsedTimer();
    }

    const restoredStep = savedProgress.currentStep;
    const isSameRestoredProgress = () => (
      Boolean(washInProgress.value) === Boolean(savedProgress.washInProgress) &&
      String(washLaneId.value ?? "") === String(savedProgress.washLaneId ?? "") &&
      String(washStartTime.value ?? "") === String(savedProgress.washStartTime ?? "") &&
      String(licensePlateInput.value ?? "") === String(savedProgress.licensePlateInput ?? "") &&
      String(vehicleTypeSelect.value ?? "") === String(savedProgress.vehicleTypeSelect ?? "") &&
      String(radioLaneOption.value ?? "") === String(savedProgress.radioLaneOption ?? "")
    );

    setTimeout(() => {
      if (isSameRestoredProgress() && currentStep.value !== restoredStep) {
        currentStep.value = restoredStep;
      }
      isRestoring.value = false;
    }, 1500);

    return savedProgress;
  };

  const registerBeforeUnload = () => {
    if (typeof window === "undefined") {
      return () => {};
    }

    beforeUnloadHandler = () => {
      markDestroying();
      saveProgress("beforeunload");
    };

    window.addEventListener("beforeunload", beforeUnloadHandler);

    return () => {
      if (beforeUnloadHandler) {
        window.removeEventListener("beforeunload", beforeUnloadHandler);
        beforeUnloadHandler = null;
      }
    };
  };

  const cleanup = () => {
    markDestroying();
    stopElapsedTimer();

    if (typeof window !== "undefined" && beforeUnloadHandler) {
      window.removeEventListener("beforeunload", beforeUnloadHandler);
      beforeUnloadHandler = null;
    }
  };

  onUnmounted(() => {
    cleanup();
  });

  return {
    completedDurationMs,
    now,
    isRestoring,
    isDestroying,
    isDestroyingManual,
    timeSinceWashStart,
    formattedElapsed,
    loadProgress,
    saveProgress,
    clearProgress,
    restoreProgress,
    startElapsedTimer,
    stopElapsedTimer,
    markDestroying,
    registerBeforeUnload,
    cleanup,
  };
}