const { get, post } = require("../../utils/api");
const { showError } = require("../../utils/page-helpers");

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

function normalizeVote(item, selectedIds) {
  const optionIds = selectedIds || item.my_option_ids || [];
  const totalVotes = (item.options || []).reduce((sum, option) => sum + Number(option.vote_count || 0), 0);
  return {
    ...item,
    status_text: item.status === "open" ? "进行中" : "已关闭",
    vote_type_text: item.vote_type === "multiple" ? `多选，最多 ${item.max_choices || 1} 项` : "单选",
    deadline_text: item.deadline ? formatDateTime(item.deadline) : "",
    can_submit: item.status === "open" && !item.has_voted,
    voted_action_text: item.has_voted ? "已参与" : "请选择",
    submit_text: item.has_voted ? "你已参与" : "投票已关闭",
    selectedIds: optionIds,
    options: (item.options || []).map((option) => {
      const voteCount = Number(option.vote_count || 0);
      const percent = totalVotes > 0 ? Math.round((voteCount / totalVotes) * 100) : 0;
      return {
        ...option,
        checked: optionIds.includes(option.id),
        selected_class: optionIds.includes(option.id) ? "selected" : "",
        check_text: optionIds.includes(option.id) ? "✓" : "",
        percent,
        percent_style: `width: ${percent}%`,
        voter_names_text: Array.isArray(option.voter_names) ? option.voter_names.join("、") : ""
      };
    })
  };
}

Page({
  data: {
    id: null,
    item: null,
    loading: false,
    submitting: false
  },

  onLoad(options) {
    wx.setNavigationBarTitle({ title: "投票详情" });
    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 item = await get(`/api/votes/${id}`);
      this.setData({ item: normalizeVote(item) });
    } catch (error) {
      showError(error, "加载投票失败");
    } finally {
      this.setData({ loading: false });
    }
  },

  toggleOption(event) {
    const optionId = Number(event.currentTarget.dataset.id);
    const item = this.data.item;
    if (!item || item.status !== "open" || item.has_voted) return;
    let selectedIds = item.selectedIds || [];
    if (item.vote_type === "single") {
      selectedIds = [optionId];
    } else if (selectedIds.includes(optionId)) {
      selectedIds = selectedIds.filter((id) => id !== optionId);
    } else {
      if (selectedIds.length >= Number(item.max_choices || 1)) {
        wx.showToast({ title: `最多选择 ${item.max_choices} 项`, icon: "none" });
        return;
      }
      selectedIds = [...selectedIds, optionId];
    }
    this.setData({ item: normalizeVote(item, selectedIds) });
  },

  async submit() {
    const item = this.data.item;
    if (!item || item.has_voted || item.status !== "open") return;
    const selectedIds = item.selectedIds || [];
    if (!selectedIds.length) {
      wx.showToast({ title: "请选择投票选项", icon: "none" });
      return;
    }
    this.setData({ submitting: true });
    try {
      await post(`/api/votes/${item.id}/submit`, { option_ids: selectedIds });
      wx.showToast({ title: "已投票", icon: "success" });
      await this.load(item.id);
    } catch (error) {
      showError(error, "投票失败");
    } finally {
      this.setData({ submitting: false });
    }
  }
});