// 公園・公共施設データの簡易エディタ（ローカル専用）。
//
// 使い方:
//   npm run park-editor
//   → 表示された URL（既定 http://localhost:8787/）をブラウザで開く
//   → タブで「市内公園 / 周辺の公園 / 市内の公共施設 / 周辺の公共施設」を切り替え
//   → 表のセルを直接編集し、「保存」を押すと該当するJSONを更新
//   → 反映確認後、git にコミットする
//
// 注意: ローカル（127.0.0.1）にのみ公開します。追加パッケージは不要です。
import { createServer } from "node:http";
import { readFile, writeFile, rename } from "node:fs/promises";
import { fileURLToPath } from "node:url";
import { dirname, join } from "node:path";

const root = join(dirname(fileURLToPath(import.meta.url)), "..");
const HTML = join(root, "scripts/park-editor.html");
const PORT = Number(process.env.PORT || 8787);

const DATASETS = {
  parks: {
    label: "市内公園",
    path: join(root, "src/data/kodaira-parks.json"),
    pretty: false,
  },
  nearbyParks: {
    label: "周辺の公園",
    path: join(root, "src/data/kodaira-nearby-parks.json"),
    pretty: false,
  },
  facilities: {
    label: "市内の公共施設",
    path: join(root, "src/data/kodaira-facilities.json"),
    pretty: true,
  },
  nearbyFacilities: {
    label: "周辺の公共施設",
    path: join(root, "src/data/kodaira-nearby-facilities.json"),
    pretty: true,
  },
};

function send(res, code, type, body) {
  res.writeHead(code, { "content-type": type });
  res.end(body);
}

function datasetFromUrl(url) {
  const match = /^\/api\/data\/([A-Za-z]+)$/.exec(url);
  if (!match) return null;
  return DATASETS[match[1]] ? { id: match[1], dataset: DATASETS[match[1]] } : null;
}

// 文字化け（U+FFFD）の場所を「レコード名 / 項目名」で返す。
// 保存は止めず、どこを直せばよいか分かるようにするための情報。
const NAME_KEYS = ["公園名", "name", "名称", "our_name"];
function recordLabel(obj) {
  const sources = [];
  if (obj && obj.properties) sources.push(obj.properties);
  sources.push(obj);
  for (const source of sources) {
    for (const key of NAME_KEYS) {
      const value = source && source[key];
      if (typeof value === "string" && value) return value;
    }
  }
  return "";
}
function findCorruptions(value, path, out) {
  if (typeof value === "string") {
    if (value.includes("\uFFFD")) out.push({ where: path, value });
  } else if (Array.isArray(value)) {
    value.forEach((item, index) => {
      const label = recordLabel(item);
      findCorruptions(item, label || `${path}[${index + 1}]`, out);
    });
  } else if (value && typeof value === "object") {
    for (const [key, child] of Object.entries(value)) {
      if (key.includes("\uFFFD")) out.push({ where: `${path} / ${key}（項目名）`, value: "" });
      findCorruptions(child, path ? `${path} / ${key}` : key, out);
    }
  }
  return out;
}

const FFFD = "\uFFFD";

function recordKey(obj) {
  const src = obj && obj.properties ? obj.properties : obj;
  if (!src) return null;
  for (const key of ["公園名", "name", "名称", "our_name"]) {
    const value = src[key];
    if (typeof value === "string" && value) return value;
  }
  return null;
}

function canonicalKeysFrom(lists) {
  const keys = new Set();
  for (const list of lists) {
    for (const rec of list || []) {
      const src = rec && rec.properties ? rec.properties : rec;
      if (!src) continue;
      for (const key of Object.keys(src)) {
        if (!key.includes(FFFD)) keys.add(key);
      }
    }
  }
  return [...keys];
}

// 「ベンチ・椅���」のような項目名の文字化けを、前後の文字から正しい項目名に戻す
function normalizeRecordKeys(rec, canonicalKeys) {
  const src = rec && rec.properties ? rec.properties : rec;
  if (!src) return;
  for (const bad of Object.keys(src)) {
    if (!bad.includes(FFFD)) continue;
    const prefix = bad.split(FFFD)[0];
    const suffix = bad.split(FFFD).slice(-1)[0];
    const candidates = canonicalKeys.filter(
      (key) => key.startsWith(prefix) && key.endsWith(suffix),
    );
    if (candidates.length !== 1) continue;
    const good = candidates[0];
    const value = src[bad];
    if (!(good in src)) {
      src[good] = value;
      delete src[bad];
    } else if (!src[good] && value) {
      src[good] = value;
      delete src[bad];
    } else if (src[good] === value) {
      delete src[bad];
    }
  }
}

// 値の文字化けが「何文字かの欠落」だけなら、ディスク側の値で直す
function repairValue(posted, current) {
  if (typeof posted !== "string" || !posted.includes(FFFD)) return posted;
  if (typeof current !== "string" || !current) return posted;
  const parts = posted.split(/\uFFFD+/);
  if (parts.length < 2) return posted;
  const pattern =
    "^" +
    parts.map((part) => part.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")).join("(.{1,4}?)") +
    "$";
  return new RegExp(pattern, "s").test(current) ? current : posted;
}

function mergeInto(target, source) {
  const dst = target.properties || target;
  const src = source.properties || source;
  for (const [field, value] of Object.entries(src)) {
    if (!(field in dst) || (!dst[field] && value)) dst[field] = value;
  }
}

// ブラウザが古いデータを持っていても、後から足した項目やレコードを消さないようにする。
// 画面になくて編集できないキーは、ディスク側の値を残す。
function mergeMissing(postedList, currentList, canonicalKeys) {
  for (const rec of postedList) normalizeRecordKeys(rec, canonicalKeys);

  // 同じレコードが重複していたら1つにまとめる
  const deduped = [];
  const byKey = new Map();
  for (const rec of postedList) {
    const key = recordKey(rec);
    if (!key) {
      deduped.push(rec);
      continue;
    }
    const existing = byKey.get(key);
    if (existing) {
      mergeInto(existing, rec);
      continue;
    }
    byKey.set(key, rec);
    deduped.push(rec);
  }
  postedList.length = 0;
  for (const rec of deduped) postedList.push(rec);

  const map = new Map();
  for (const rec of currentList) {
    const key = recordKey(rec);
    if (key) map.set(key, rec);
  }
  const postedKeys = new Set();
  for (const rec of postedList) {
    const key = recordKey(rec);
    if (!key) continue;
    postedKeys.add(key);
    const current = map.get(key);
    if (!current) continue;
    const dst = rec.properties || rec;
    const src = current.properties || current;
    for (const [field, value] of Object.entries(src)) {
      if (!(field in dst)) {
        dst[field] = value;
      } else if (typeof dst[field] === "string" && dst[field].includes(FFFD)) {
        dst[field] = repairValue(dst[field], value);
      }
    }
  }
  for (const [key, rec] of map) {
    if (!postedKeys.has(key)) postedList.push(rec);
  }
}

const server = createServer(async (req, res) => {
  try {
    const url = (req.url || "").split("?")[0];
    if (req.method === "GET" && (url === "/" || url === "/index.html")) {
      send(res, 200, "text/html; charset=utf-8", await readFile(HTML, "utf-8"));
      return;
    }

    if (req.method === "GET" && url === "/api/datasets") {
      send(
        res,
        200,
        "application/json; charset=utf-8",
        JSON.stringify(
          Object.entries(DATASETS).map(([id, dataset]) => ({ id, label: dataset.label })),
        ),
      );
      return;
    }

    const target = datasetFromUrl(url);
    if (!target) {
      send(res, 404, "text/plain; charset=utf-8", "not found");
      return;
    }

    if (req.method === "GET") {
      send(
        res,
        200,
        "application/json; charset=utf-8",
        await readFile(target.dataset.path, "utf-8"),
      );
      return;
    }

    if (req.method === "POST") {
      let body = "";
      for await (const chunk of req) body += chunk;
      const data = JSON.parse(body);

      if (target.id === "nearbyParks") {
        if (!data || data.type !== "FeatureCollection" || !Array.isArray(data.features)) {
          throw new Error("周辺の公園は FeatureCollection ではありません");
        }
      } else if (!Array.isArray(data) || data.length === 0) {
        throw new Error("データが配列ではありません");
      }

      // 古い画面からの保存で、新しい項目・レコードが消えないようにマージする
      const current = JSON.parse(await readFile(target.dataset.path, "utf-8"));
      const canonicalKeys = canonicalKeysFrom([current, data.features || data]);
      if (target.id === "nearbyParks") {
        mergeMissing(data.features, current.features || [], canonicalKeys);
      } else {
        mergeMissing(data, current, canonicalKeys);
      }

      const text = target.dataset.pretty
        ? `${JSON.stringify(data, null, 2)}\n`
        : `${JSON.stringify(data)}\n`;
      if (text.includes("\uFFFD")) {
        // 保存は中止せず、どこが文字化けしているかを返す（入力内容を失わないため）
        console.warn("文字化け（U+FFFD）を含むデータを保存しました");
      }
      const warnings = findCorruptions(data, "", []).slice(0, 50);
      if (warnings.length) {
        for (const warning of warnings.slice(0, 10)) {
          console.warn(`  文字化け: ${warning.where} = ${warning.value}`);
        }
      }
      const tmp = `${target.dataset.path}.tmp`;
      await writeFile(tmp, text, "utf-8");
      await rename(tmp, target.dataset.path);

      const count = target.id === "nearbyParks" ? data.features.length : data.length;
      console.log(`保存しました: ${target.dataset.label} ${count}件 → ${target.dataset.path}`);
      send(
        res,
        200,
        "application/json; charset=utf-8",
        JSON.stringify({ ok: true, count, warnings }),
      );
      return;
    }

    send(res, 405, "text/plain; charset=utf-8", "method not allowed");
  } catch (e) {
    console.error(e);
    send(res, 500, "text/plain; charset=utf-8", String(e));
  }
});

server.listen(PORT, "127.0.0.1", () => {
  console.log(`公園・施設データ編集: http://localhost:${PORT}/  （Ctrl+C で終了）`);
});