const { del, get, put, uploadFile } = require("../../utils/api");
const { hasManagePermission } = require("../../utils/permissions");
const { showError } = require("../../utils/page-helpers");

const FUND_INCOME_CATEGORIES = ["班费收取", "活动赞助", "其他收入"];
const FUND_EXPENSE_CATEGORIES = ["聚餐", "活动物资", "场地费", "交通费", "礼品", "其他支出"];

function formatAmount(value) {
  return Number(value || 0).toFixed(2);
}

function formatDateTime(value) {
  if (!value) return "";
  return String(value).replace("T", " ").slice(0, 16);
}

function normalizeRecord(record) {
  const isIncome = record.type === "income";
  const imageUrls = Array.isArray(record.image_urls) ? record.image_urls : [];
  return {
    ...record,
    amount_text: formatAmount(record.amount),
    signed_amount_text: `${isIncome ? "+" : "-"}¥${formatAmount(record.amount)}`,
    type_text: isIncome ? "收入" : "支出",
    type_class: isIncome ? "income" : "expense",
    image_urls: imageUrls,
    image_count_text: imageUrls.length ? `${imageUrls.length} 张凭证` : "未上传凭证",
    created_at_text: formatDateTime(record.created_at),
    updated_at_text: formatDateTime(record.updated_at)
  };
}

Page({
  data: {
    id: null,
    record: null,
    canManage: false,
    editOpen: false,
    editForm: {},
    editImageUrls: [],
    editCategories: FUND_EXPENSE_CATEGORIES,
    editIncomeClass: "",
    editExpenseClass: "active expense",
    loading: false,
    saving: false,
    deleting: false,
    uploadingImages: false
  },

  onLoad(options) {
    wx.setNavigationBarTitle({ title: "班费详情" });
    this.setData({ id: options.id || null });
    this.load(options.id);
  },

  async onPullDownRefresh() {
    await this.load(this.data.id);
    wx.stopPullDownRefresh();
  },

  async load(id) {
    if (!id) return;
    this.setData({ loading: true });
    try {
      const record = await get(`/api/fund/${id}`);
      const user = getApp().globalData.user || wx.getStorageSync("auth_user");
      const canManage = hasManagePermission(user, record.class_id, "fund");
      this.setData({ record: normalizeRecord(record), canManage });
    } catch (error) {
      showError(error, "加载班费详情失败");
    } finally {
      this.setData({ loading: false });
    }
  },

  previewImage(event) {
    const current = event.currentTarget.dataset.src;
    const urls = this.data.record && this.data.record.image_urls ? this.data.record.image_urls : [];
    if (!current || !urls.length) return;
    wx.previewImage({ current, urls });
  },

  noop() {},

  openEdit() {
    const record = this.data.record;
    if (!record || !this.data.canManage) return;
    const categories = record.type === "income" ? FUND_INCOME_CATEGORIES : FUND_EXPENSE_CATEGORIES;
    this.setData({
      editOpen: true,
      editForm: {
        type: record.type,
        amount: String(record.amount || ""),
        category: record.category || categories[0],
        description: record.description || "",
        record_date: record.record_date || ""
      },
      editImageUrls: [...record.image_urls],
      editCategories: categories,
      editIncomeClass: record.type === "income" ? "active income" : "",
      editExpenseClass: record.type === "expense" ? "active expense" : ""
    });
  },

  closeEdit() {
    if (this.data.saving || this.data.uploadingImages) return;
    this.setData({ editOpen: false });
  },

  onEditInput(event) {
    const field = event.currentTarget.dataset.field;
    this.setData({ [`editForm.${field}`]: event.detail.value });
  },

  setEditFundType(event) {
    const type = event.currentTarget.dataset.type;
    const categories = type === "income" ? FUND_INCOME_CATEGORIES : FUND_EXPENSE_CATEGORIES;
    this.setData({
      "editForm.type": type,
      "editForm.category": categories[0],
      editCategories: categories,
      editIncomeClass: type === "income" ? "active income" : "",
      editExpenseClass: type === "expense" ? "active expense" : ""
    });
  },

  onEditCategoryChange(event) {
    const index = Number(event.detail.value);
    this.setData({ "editForm.category": this.data.editCategories[index] });
  },

  onEditDateChange(event) {
    this.setData({ "editForm.record_date": event.detail.value });
  },

  chooseEditImages() {
    if (this.data.uploadingImages) return;
    if (this.data.editImageUrls.length >= 6) {
      wx.showToast({ title: "最多 6 张图片", icon: "none" });
      return;
    }
    wx.chooseMedia({
      count: 6 - this.data.editImageUrls.length,
      mediaType: ["image"],
      sourceType: ["album", "camera"],
      success: async (res) => {
        const paths = (res.tempFiles || []).map((item) => item.tempFilePath);
        if (!paths.length) return;
        this.setData({ uploadingImages: true });
        try {
          const uploaded = [...this.data.editImageUrls];
          for (const path of paths) {
            const result = await uploadFile("/api/upload/image", path, {}, "file");
            if (result && result.url) uploaded.push(result.url);
          }
          this.setData({ editImageUrls: uploaded.slice(0, 6) });
        } catch (error) {
          showError(error, "上传图片失败");
        } finally {
          this.setData({ uploadingImages: false });
        }
      }
    });
  },

  removeEditImage(event) {
    const index = Number(event.currentTarget.dataset.index);
    this.setData({
      editImageUrls: this.data.editImageUrls.filter((_, itemIndex) => itemIndex !== index)
    });
  },

  async saveEdit() {
    if (this.data.saving || this.data.uploadingImages) return;
    const form = this.data.editForm;
    const amount = Number(form.amount);
    if (!amount || amount <= 0) {
      wx.showToast({ title: "请输入有效金额", icon: "none" });
      return;
    }
    if (!form.category) {
      wx.showToast({ title: "请选择分类", icon: "none" });
      return;
    }
    if (!form.record_date) {
      wx.showToast({ title: "请选择日期", icon: "none" });
      return;
    }
    this.setData({ saving: true });
    try {
      const updated = await put(`/api/fund/${this.data.id}`, {
        type: form.type,
        amount,
        category: form.category,
        description: form.description || null,
        image_urls: this.data.editImageUrls,
        record_date: form.record_date
      });
      this.setData({
        record: normalizeRecord(updated),
        editOpen: false
      });
      this.refreshPreviousPage();
      wx.showToast({ title: "已更新", icon: "success" });
    } catch (error) {
      showError(error, "保存失败");
    } finally {
      this.setData({ saving: false });
    }
  },

  deleteRecord() {
    if (this.data.deleting || !this.data.canManage || !this.data.record) return;
    wx.showModal({
      title: "删除班费记录",
      content: "删除后无法恢复，确认删除这条班费记录？",
      confirmText: "删除",
      confirmColor: "#b42318",
      success: async (res) => {
        if (!res.confirm) return;
        this.setData({ deleting: true });
        try {
          await del(`/api/fund/${this.data.id}`);
          this.refreshPreviousPage();
          wx.showToast({ title: "已删除", icon: "success" });
          setTimeout(() => wx.navigateBack(), 500);
        } catch (error) {
          showError(error, "删除失败");
        } finally {
          this.setData({ deleting: false });
        }
      }
    });
  },

  refreshPreviousPage() {
    const pages = getCurrentPages();
    const previousPage = pages[pages.length - 2];
    if (previousPage && previousPage.load) {
      previousPage.load();
    }
  }
});