import { api } from "../api.js";
import {
  centerActiveChips, chip, emptyState, pager, upCard, videoCard,
} from "../components.js";
import { escapeAttr, escapeHtml, formatCount, formatDate, formatNumber, formatPercent } from "../format.js";
import { replaceQuery } from "../router.js";

const VIDEO_SORTS = [
  ["efficiency", "内容效率"],
  ["heat", "综合热度"],
  ["published", "发布时间"],
  ["added", "入库时间"],
  ["view", "播放"],
  ["coin", "投币"],
  ["favorite", "收藏"],
  ["reply", "评论"],
  ["interaction", "互动率"],
  ["growth", "播放增量"],
  ["growth_rate", "播放增速"],
];
const UP_SORTS = [
  ["efficiency", "内容效率"],
  ["interaction_efficiency", "互动效率"],
  ["duration", "内容量"],
  ["views", "总播放"],
  ["count", "视频数"],
  ["avg_views", "平均播放"],
  ["interaction", "总互动"],
  ["latest", "最近发布"],
];
const TIME_RANGES = [
  ["all", "全部时间"],
  ["7", "近 7 天"],
  ["30", "近 30 天"],
  ["90", "近 90 天"],
  ["365", "近 1 年"],
];
const VIDEO_METRIC_PRIMARY = new Set(["view", "coin", "favorite", "reply"]);
const OVERVIEW_TTL = 60_000;
let overviewCache = { at: 0, promise: null };

async function getOverview() {
  const now = Date.now();
  if (!overviewCache.promise || now - overviewCache.at > OVERVIEW_TTL) {
    overviewCache = { at: now, promise: api("/api/overview") };
  }
  try {
    return await overviewCache.promise;
  } catch (error) {
    overviewCache = { at: 0, promise: null };
    throw error;
  }
}

function sortOptions(scope, sort) {
  const sorts = scope === "up" ? UP_SORTS : VIDEO_SORTS;
  return sorts.map(([value, label]) =>
    `<option value="${value}" ${value === sort ? "selected" : ""}>${escapeHtml(label)}</option>`).join("");
}

function timeOptions(within, year, years) {
  const selected = year ? `year:${year}` : (within || "all");
  const base = TIME_RANGES.map(([value, label]) =>
    `<option value="${value}" ${selected === value ? "selected" : ""}>${escapeHtml(label)}</option>`).join("");
  const yearOptions = (years || []).map((value) =>
    `<option value="year:${value}" ${selected === `year:${value}` ? "selected" : ""}>${value} 年</option>`).join("");
  return base + yearOptions;
}

function controls({ scope, sort, within, year, growthDays, q, minVideos, years }) {
  return `
    <div class="rank-toolbar">
      <form class="rank-search" id="rank-filter">
        <input class="search-input" type="search" name="q" value="${escapeAttr(q || "")}"
          placeholder="${scope === "up" ? "搜索 UP 名" : "搜索标题或 UP"}" autocomplete="off">
        <button class="button" type="submit">搜索</button>
      </form>
      <label class="select-label">排序
        <select class="select" id="rank-sort">${sortOptions(scope, sort)}</select>
      </label>
      <label class="select-label">时间
        <select class="select" id="rank-time">${timeOptions(within, year, years)}</select>
      </label>
      ${scope === "up" ? `<label class="select-label">视频数
        <select class="select" id="min-videos">
          <option value="1" ${String(minVideos) === "1" ? "selected" : ""}>全部 UP</option>
          <option value="2" ${String(minVideos) === "2" ? "selected" : ""}>≥ 2 条</option>
          <option value="5" ${String(minVideos) === "5" ? "selected" : ""}>≥ 5 条</option>
        </select>
      </label>` : ""}
    </div>
    ${scope === "video" && (sort === "growth" || sort === "growth_rate") ? `
      <div class="chip-row growth-days">
        <span class="chip-label">增长区间</span>
        ${[[1, "1 天"], [7, "7 天"], [30, "30 天"]]
          .map(([value, label]) => chip(label, Number(growthDays) === value, "growth-days", value)).join("")}
      </div>` : ""}
  `;
}

function videoPrimary(item, sort) {
  if (sort === "efficiency") {
    return { primary: "efficiency_score", label: "播放/小时·收缩", text: formatCount(item.efficiency_score) };
  }
  if (sort === "interaction_efficiency") {
    return { primary: "interaction_efficiency_score", label: "互动/小时·收缩", text: formatCount(item.interaction_efficiency_score) };
  }
  if (sort === "interaction") {
    return { primary: "view", label: "互动率", text: formatPercent(item.interaction_rate) };
  }
  if (VIDEO_METRIC_PRIMARY.has(sort)) {
    return { primary: sort, label: "", text: null };
  }
  return { primary: "view", label: "播放", text: null };
}

function upPrimary(item, sort) {
  if (sort === "efficiency") {
    return { label: "播放/小时", text: formatCount(item.efficiency) };
  }
  if (sort === "interaction_efficiency") {
    return { label: "互动/小时", text: formatCount(item.interaction_efficiency) };
  }
  if (sort === "duration") {
    return { label: "内容小时", text: item.content_hours === null ? "—" : `${formatNumber(item.content_hours)} 小时` };
  }
  if (sort === "views") return { label: "总播放", text: formatCount(item.total_views) };
  if (sort === "count") return { label: "视频数", text: formatNumber(item.video_count) };
  if (sort === "avg_views") return { label: "平均播放", text: formatCount(item.avg_views) };
  if (sort === "avg_interaction") return { label: "平均互动", text: formatPercent(item.avg_interaction) };
  if (sort === "interaction") return { label: "总互动", text: formatCount(item.total_interactions) };
  if (sort === "latest") return { label: "最近发布", text: formatDate(item.latest_pubdate) };
  return { label: "播放/小时", text: formatCount(item.efficiency) };
}

function listHtml(data, scope, sort, startRank) {
  if (!data.items.length) {
    return emptyState(
      data.available === false ? "当前榜单暂不可用" : (scope === "up" ? "没有匹配的 UP" : "没有匹配的视频"),
      data.reason || "换个筛选条件或清空搜索关键词试试。",
    );
  }
  if (scope === "up") {
    return `<div class="rank-list">${data.items.map((item, index) => {
      const primary = upPrimary(item, sort);
      return upCard(item, {
        rank: startRank + index, primaryLabel: primary.label, primaryText: primary.text,
      });
    }).join("")}</div>`;
  }
  return `<div class="rank-list">${data.items.map((item, index) => {
    const primary = videoPrimary(item, sort);
    return videoCard(item, {
      rank: startRank + index, primary: primary.primary,
      primaryLabel: primary.label, primaryText: primary.text,
    });
  }).join("")}</div>`;
}

function durationNote(data) {
  const filter = data.duration_filter;
  if (!filter) return "";
  const shrink = filter.shrink_minutes
    ? `并按 ${filter.shrink_minutes} 分钟的先验暴露量向全库均值收缩`
    : "";
  return `<div class="section-note">内容效率与互动效率仅统计时长 ≥ ${filter.min_duration_seconds} 秒、
    发布满 ${filter.maturity_days} 天、播放 ≥ ${filter.min_view} 的视频${shrink}；时长缺失的视频不参与排序。</div>`;
}

function bindControls(root) {
  root.querySelector("#rank-sort")?.addEventListener("change", (event) => {
    replaceQuery({ sort: event.target.value, page: null });
  });
  root.querySelector("#rank-time")?.addEventListener("change", (event) => {
    const value = event.target.value;
    if (value.startsWith("year:")) {
      replaceQuery({ year: value.slice(5), within_days: null, page: null });
    } else if (value === "all") {
      replaceQuery({ year: null, within_days: null, page: null });
    } else {
      replaceQuery({ year: null, within_days: value, page: null });
    }
  });
  root.querySelectorAll("[data-growth-days]").forEach((button) => button.addEventListener("click", () => {
    replaceQuery({ growth_days: button.dataset.growthDays, page: null });
  }));
  root.querySelector("#min-videos")?.addEventListener("change", (event) => {
    replaceQuery({ min_videos: event.target.value, page: null });
  });
  root.querySelector("#rank-filter")?.addEventListener("submit", (event) => {
    event.preventDefault();
    const value = new FormData(event.target).get("q") || "";
    replaceQuery({ q: String(value).trim() || null, page: null });
  });
  root.querySelectorAll("[data-page]").forEach((button) => button.addEventListener("click", () => {
    if (button.disabled) return;
    replaceQuery({ page: button.dataset.page });
  }));
  centerActiveChips(root);
}

async function renderScope(root, { query }, scope) {
  const sort = query.get("sort") || "efficiency";
  const within = query.get("within_days") || "";
  const year = query.get("year") || "";
  const growthDays = query.get("growth_days") || "7";
  const q = query.get("q") || "";
  const minVideos = query.get("min_videos") || "1";
  const page = Math.max(1, Number(query.get("page") || 1));

  const overview = await getOverview();
  const years = overview.years || [];

  const params = {
    sort,
    page,
    page_size: 20,
    within_days: within || null,
    year: year || null,
    growth_days: growthDays,
    q,
  };
  let data;
  if (scope === "up") {
    data = await api("/api/ups", { ...params, min_videos: minVideos });
  } else {
    data = await api("/api/videos", params);
  }

  const startRank = (data.page - 1) * data.page_size + 1;
  const title = scope === "up" ? "UP主" : "视频";
  const unit = scope === "up" ? "个 UP" : "条视频";

  root.innerHTML = `<section class="page rankings-page">
    <header class="page-head">
      <h1>${title} <span class="page-sub">共 ${formatCount(data.total)} ${unit}</span></h1>
    </header>
    ${controls({ scope, sort, within, year, growthDays, q, minVideos, years })}
    ${durationNote(data)}
    ${data.available === false ? `<div class="notice-row warning">
      <strong>${sort.startsWith("growth") ? "增长数据尚不可用" : "榜单筛选后为空"}</strong>
      <span>${escapeHtml(data.reason || "")}</span>
    </div>` : ""}
    ${listHtml(data, scope, sort, startRank)}
    ${pager(data.page, data.pages)}
  </section>`;

  bindControls(root);
}

export function renderVideos(root, context) {
  return renderScope(root, context, "video");
}

export function renderUps(root, context) {
  return renderScope(root, context, "up");
}