import fs from 'fs';
import path from 'path';
import { postComment, postPullReviewComment, postPullReview } from './gitea.js';
import { FINDINGS_PATH } from './config.js';
import { ok, line, warn } from './log.js';

const LEVEL_EMOJI = { critical: '🔴', warning: '🟡', info: '🔵' };
const LEVEL_LABEL = { critical: '嚴重', warning: '警告', info: '建議' };
const LEVEL_ORDER = ['critical', 'warning', 'info'];

function findingRow(f) {
  return `| ${LEVEL_EMOJI[f.level] || ''} ${LEVEL_LABEL[f.level] || f.level} | ${f.role} | ${f.location} | ${f.suggestion} |`;
}

function buildTable(findings) {
  const rows = findings.map(findingRow).join('\n');
  return `| 等級 | 審查員 | 位置 | 建議 |\n|------|--------|------|------|\n${rows}`;
}

const levelText = f => `${LEVEL_EMOJI[f.level] || ''} ${LEVEL_LABEL[f.level] || f.level}`.trim();
const bySeverity = (a, b) => {
  const aLevel = LEVEL_ORDER.includes(a.level) ? LEVEL_ORDER.indexOf(a.level) : LEVEL_ORDER.length;
  const bLevel = LEVEL_ORDER.includes(b.level) ? LEVEL_ORDER.indexOf(b.level) : LEVEL_ORDER.length;
  if (aLevel !== bLevel) return aLevel - bLevel;
  return String(a.location || '').localeCompare(String(b.location || ''));
};

/**
 * 解析 finding 的 location 取出檔案與行號，供行內 comment 標註使用。
 * 支援 "file:19" 與 "file:70-82"（取起始行）；無行號或含多個檔案（逗號）時回傳 null。
 */
export function parseLocation(location) {
  if (typeof location !== 'string') return null;
  const trimmed = location.trim();
  if (trimmed.includes(',')) return null;
  const match = trimmed.match(/^(.+?):(\d+)(?:-\d+)?$/);
  if (!match) return null;
  return { file: match[1], line: Number(match[2]) };
}

/** 行內 comment 內容：等級／審查員／建議 */
function inlineCommentBody(f) {
  return `**等級**：${levelText(f)}\n**審查員**：${f.role}\n**建議**：${f.suggestion}`;
}

function problemText(f) {
  return f.problem || f.title || f.message || f.location || '未提供問題位置';
}

function reviewCommentBody(f) {
  return [
    `**嚴重等級**：${levelText(f)}`,
    `**審查員**：${f.role}`,
    `**問題**：${problemText(f)}`,
    `**建議**：${f.suggestion}`,
  ].join('\n');
}

function countBy(findings, predicate) {
  return findings.filter(predicate).length;
}

function buildReviewSummary(findings, commentable) {
  const unplacedCount = findings.length - commentable.length;
  const criticalCount = countBy(findings, f => f.level === 'critical');
  const warningCount = countBy(findings, f => f.level === 'warning');
  const infoCount = countBy(findings, f => f.level === 'info');
  return [
    '## AI Code Review 統計',
    '',
    '| 統計 | 統計 | 統計 |',
    '| --- | --- | --- |',
    `| **總問題**<br>${findings.length} 筆 | **可標註檔案與行數**<br>${commentable.length} 筆 | **無法標註檔案與行數**<br>${unplacedCount} 筆 |`,
    `| **🔴 嚴重**<br>${criticalCount} 筆 | **🟡 警告**<br>${warningCount} 筆 | **🔵 建議**<br>${infoCount} 筆 |`,
  ].join('\n');
}

function toReviewComment(f) {
  const loc = parseLocation(f.location);
  if (!loc) return null;
  return {
    path: loc.file,
    body: reviewCommentBody(f),
    new_position: loc.line,
  };
}

/**
 * 發布單一 Gitea review：本文統計可找出檔案與行數的問題，
 * comments 只包含可定位到檔案與行數的 findings，並依嚴重等級排序。
 */
export async function postFindingsReview(findings, deps = {}) {
  const { postReview = postPullReview } = deps;
  const sorted = [...findings].sort(bySeverity);
  const comments = sorted.map(toReviewComment).filter(Boolean);
  const body = buildReviewSummary(sorted, comments);
  await postReview({ body, comments });
  ok(`review 發布: total=${sorted.length} commentable=${comments.length}`);
}

/**
 * 寫入 findings.json。
 * 預設寫到 workspace；若提供 mirrorDir，則同步寫入另一份供 repo commit 使用。
 */
export function saveFindings(workspace, findings, mirrorDir = null) {
  const targets = [workspace];
  if (mirrorDir && mirrorDir !== workspace) targets.push(mirrorDir);

  for (const targetDir of targets) {
    const fullPath = path.join(targetDir, FINDINGS_PATH);
    fs.mkdirSync(path.dirname(fullPath), { recursive: true });
    fs.writeFileSync(fullPath, JSON.stringify(findings, null, 2) + '\n', 'utf8');
    ok(`findings 寫入: ${fullPath} (${findings.length} 筆)`);
  }
}

/**
 * 發布所有舊問題 comment（一次發布，依等級排序）
 */
export async function postOldFindingsComment(findings) {
  const old = findings.filter(f => !f.is_new);
  if (old.length === 0) {
    line('無舊問題，跳過');
    return;
  }
  const body = `## 📋 舊有未解決問題（${old.length} 筆）\n\n${buildTable(old)}`;
  await postComment(body);
  ok(`舊問題 comment 發布 (${old.length} 筆)`);
}

/**
 * 發布新問題中非 critical 的 comment（一次發布）
 */
export async function postNewNonCriticalComment(findings) {
  const items = findings.filter(f => f.is_new && f.level !== 'critical');
  if (items.length === 0) {
    line('無新的非嚴重問題，跳過');
    return;
  }
  const body = `## 🔍 新發現問題（${items.length} 筆）\n\n${buildTable(items)}`;
  await postComment(body);
  ok(`新問題（非嚴重）comment 發布 (${items.length} 筆)`);
}

/**
 * 每個新 critical 問題各發一個 comment。
 * 優先用 Gitea 行內 review comment 標註問題檔案與行數（內容為等級／審查員／建議）；
 * 若 location 無法解析出行號，或行內發布失敗（例如該行不在 diff 範圍），則降級為一般 comment。
 */
export async function postNewCriticalComments(findings, deps = {}) {
  const { postInline = postPullReviewComment, postIssue = postComment } = deps;
  const criticals = findings.filter(f => f.is_new && f.level === 'critical');
  if (criticals.length === 0) {
    line('無新的嚴重問題，跳過');
    return;
  }
  for (const f of criticals) {
    const loc = parseLocation(f.location);
    if (loc) {
      try {
        await postInline({ path: loc.file, line: loc.line, body: inlineCommentBody(f) });
        ok(`嚴重問題 行內 comment 發布: [${f.role}] ${loc.file}:${loc.line}`);
        continue;
      } catch (e) {
        warn(`行內 comment 發布失敗，改用一般 comment: [${f.role}] ${f.location} error=${e.message}`);
      }
    }
    await postIssue(`## 🚨 嚴重問題\n\n${buildTable([f])}`);
    ok(`嚴重問題 comment 發布: [${f.role}] ${f.location}`);
  }
}