# 评论认领：在 Issue 下评论「我想做」等关键词后，自动指派/标记认领人。
# 说明：
# - 仓库协作者（write 及以上）可成功写入 Assignees
# - 外部贡献者若无写权限，GitHub 不允许设为 assignee；此时会打 claimed 标签并回复确认
# - 支持取消认领：取消认领 / /unclaim
name: Issue Claim

on:
  issue_comment:
    types: [created]

permissions:
  issues: write
  contents: read

jobs:
  claim:
    name: Auto claim or unclaim
    if: ${{ !github.event.issue.pull_request }}
    runs-on: ubuntu-latest
    steps:
      - name: Process claim / unclaim comment
        uses: actions/github-script@v7
        with:
          script: |
            const issue = context.payload.issue;
            const comment = context.payload.comment;
            const actor = comment.user.login;
            const actorType = comment.user.type;

            // 忽略机器人自己的评论，避免循环
            if (actorType === 'Bot') {
              core.info('Skip bot comment');
              return;
            }

            const raw = (comment.body || '').replace(/\r\n/g, '\n').trim();
            if (!raw) {
              return;
            }

            // 仅认领短指令：整段或首行匹配，避免长讨论误触发
            const firstLine = raw.split('\n').map((l) => l.trim()).find(Boolean) || '';
            const normalize = (s) =>
              s
                .replace(/^[@/]/g, '')
                .replace(/[！!。．.、,，\s]+$/g, '')
                .trim()
                .toLowerCase();

            const claimPhrases = new Set([
              '我想做',
              '我来做',
              '我来',
              '认领',
              '我认领',
              'claim',
              'i claim',
              'i want this',
              'i will take this',
              'assign me',
            ]);
            const unclaimPhrases = new Set([
              '取消认领',
              '不认领了',
              '放弃认领',
              'unclaim',
              'release',
            ]);

            const nFull = normalize(raw);
            const nFirst = normalize(firstLine);
            // 允许 /claim /unclaim 形式
            const slash = firstLine.match(/^\/(claim|unclaim)\b/i);
            const isClaim =
              claimPhrases.has(nFull) ||
              claimPhrases.has(nFirst) ||
              (slash && slash[1].toLowerCase() === 'claim');
            const isUnclaim =
              unclaimPhrases.has(nFull) ||
              unclaimPhrases.has(nFirst) ||
              (slash && slash[1].toLowerCase() === 'unclaim');

            if (!isClaim && !isUnclaim) {
              core.info('Comment is not a claim/unclaim command');
              return;
            }

            const owner = context.repo.owner;
            const repo = context.repo.repo;
            const issue_number = issue.number;
            const CLAIMED_LABEL = 'claimed';

            async function ensureClaimedLabel() {
              try {
                await github.rest.issues.getLabel({ owner, repo, name: CLAIMED_LABEL });
              } catch (e) {
                if (e.status !== 404) throw e;
                await github.rest.issues.createLabel({
                  owner,
                  repo,
                  name: CLAIMED_LABEL,
                  color: '0E8A16',
                  description: '已被社区认领，进行中',
                });
              }
            }

            async function ensureLabels(names) {
              const current = new Set((issue.labels || []).map((l) => (typeof l === 'string' ? l : l.name)));
              const toAdd = names.filter((n) => !current.has(n));
              if (toAdd.length) {
                await github.rest.issues.addLabels({ owner, repo, issue_number, labels: toAdd });
              }
            }

            async function removeLabels(names) {
              for (const name of names) {
                try {
                  await github.rest.issues.removeLabel({ owner, repo, issue_number, name });
                } catch (e) {
                  if (e.status !== 404) throw e;
                }
              }
            }

            async function tryAssign(login) {
              try {
                await github.rest.issues.addAssignees({
                  owner,
                  repo,
                  issue_number,
                  assignees: [login],
                });
                return { ok: true };
              } catch (e) {
                const msg = e.message || String(e);
                core.warning(`assign failed for ${login}: ${msg}`);
                return { ok: false, message: msg };
              }
            }

            async function tryUnassign(login) {
              try {
                await github.rest.issues.removeAssignees({
                  owner,
                  repo,
                  issue_number,
                  assignees: [login],
                });
                return { ok: true };
              } catch (e) {
                core.warning(`unassign failed for ${login}: ${e.message || e}`);
                return { ok: false };
              }
            }

            // 从 issue 正文底部的认领锚点解析当前认领人
            const CLAIM_MARKER_RE =
              /<!--\s*gonavi-claim\s*:\s*([A-Za-z0-9-]+)\s*-->/;
            const body = issue.body || '';
            const markerMatch = body.match(CLAIM_MARKER_RE);
            const markerClaimer = markerMatch ? markerMatch[1] : null;
            const assignees = (issue.assignees || []).map((a) => a.login);
            const currentClaimer = assignees[0] || markerClaimer || null;
            const hasClaimedLabel = (issue.labels || []).some(
              (l) => (typeof l === 'string' ? l : l.name) === CLAIMED_LABEL
            );

            if (isUnclaim) {
              if (!currentClaimer && !hasClaimedLabel) {
                await github.rest.issues.createComment({
                  owner,
                  repo,
                  issue_number,
                  body: `ℹ️ @${actor} 当前无人认领，无需取消。`,
                });
                return;
              }
              if (currentClaimer && currentClaimer.toLowerCase() !== actor.toLowerCase()) {
                // 仅认领人本人可取消；维护者可强制取消
                const isMaintainer = ['OWNER', 'MEMBER', 'COLLABORATOR'].includes(
                  context.payload.comment.author_association
                );
                if (!isMaintainer) {
                  await github.rest.issues.createComment({
                    owner,
                    repo,
                    issue_number,
                    body: `⚠️ @${actor} 本 Issue 当前由 @${currentClaimer} 认领。请对方评论 \`取消认领\`，或联系维护者。`,
                  });
                  return;
                }
              }

              const who = currentClaimer || actor;
              await tryUnassign(who);
              await removeLabels([CLAIMED_LABEL]);

              let newBody = body;
              if (CLAIM_MARKER_RE.test(newBody)) {
                newBody = newBody
                  .replace(/\n?<!--\s*gonavi-claim\s*:\s*[A-Za-z0-9-]+\s*-->\s*/g, '\n')
                  .replace(/\n?### 🔐 认领状态[\s\S]*?(?=\n## |\n# |$)/, '\n')
                  .trimEnd();
                await github.rest.issues.update({ owner, repo, issue_number, body: newBody });
              }

              await github.rest.issues.createComment({
                owner,
                repo,
                issue_number,
                body: `🔓 @${actor} 已取消认领${who !== actor ? `（原认领人 @${who}）` : ''}。其他人可评论 \`我想做\` 重新认领。`,
              });
              return;
            }

            // —— claim ——
            if (currentClaimer && currentClaimer.toLowerCase() !== actor.toLowerCase()) {
              await github.rest.issues.createComment({
                owner,
                repo,
                issue_number,
                body: `⚠️ @${actor} 本 Issue 已由 @${currentClaimer} 认领。\n\n- 若对方长期无进展，可评论提醒，或由维护者 \`取消认领\` 后重开\n- 你也可以先在本线程说明想做的方向，维护者可协助拆分子任务`,
              });
              return;
            }

            if (currentClaimer && currentClaimer.toLowerCase() === actor.toLowerCase()) {
              await github.rest.issues.createComment({
                owner,
                repo,
                issue_number,
                body: `✅ @${actor} 你已经是本 Issue 的认领人，无需重复认领。开干吧 💪`,
              });
              return;
            }

            await ensureClaimedLabel();
            const assignResult = await tryAssign(actor);
            await ensureLabels([CLAIMED_LABEL]);

            // 在正文写入可机读认领锚点（assignee 失败时仍可防双认领）
            const stamp = new Date().toISOString().slice(0, 10);
            const claimBlock =
              `\n\n### 🔐 认领状态\n\n` +
              `- 认领人：@${actor}\n` +
              `- 认领日期：${stamp}\n` +
              `- 取消方式：评论 \`取消认领\` 或 \`/unclaim\`\n` +
              `<!-- gonavi-claim: ${actor} -->\n`;

            let newBody = body;
            if (CLAIM_MARKER_RE.test(newBody)) {
              newBody = newBody.replace(
                CLAIM_MARKER_RE,
                `<!-- gonavi-claim: ${actor} -->`
              );
              if (!/### 🔐 认领状态/.test(newBody)) {
                newBody = newBody.trimEnd() + claimBlock;
              }
            } else {
              newBody = newBody.trimEnd() + claimBlock;
            }
            await github.rest.issues.update({ owner, repo, issue_number, body: newBody });

            if (assignResult.ok) {
              await github.rest.issues.createComment({
                owner,
                repo,
                issue_number,
                body:
                  `✅ @${actor} 已认领本 Issue，并已加入 **Assignees**。\n\n` +
                  `建议下一步：\n` +
                  `1. 从 \`dev\` 拉分支：\`fix/*\` 或 \`feature/*\`\n` +
                  `2. 完成后向 **\`dev\`** 提 PR\n` +
                  `3. 若暂无法继续，请评论 \`取消认领\`\n\n` +
                  `贡献指南：https://github.com/Syngnat/GoNavi/blob/dev/CONTRIBUTING.zh-CN.md`,
              });
            } else {
              await github.rest.issues.createComment({
                owner,
                repo,
                issue_number,
                body:
                  `✅ @${actor} 已认领本 Issue（已标记 \`claimed\`）。\n\n` +
                  `> 说明：GitHub 仅允许将**仓库协作者**设为正式 Assignee。你目前可能还没有写权限，因此无法写入 Assignees 字段；**社区认领仍然有效**，其他人再评论「我想做」会被拦截。\n\n` +
                  `建议下一步：\n` +
                  `1. Fork 仓库，从 \`dev\` 拉分支开发\n` +
                  `2. 向 **\`dev\`** 提 PR，并在 PR 描述里写 \`Fixes #${issue_number}\`\n` +
                  `3. 若暂无法继续，请评论 \`取消认领\`\n\n` +
                  `贡献指南：https://github.com/Syngnat/GoNavi/blob/dev/CONTRIBUTING.zh-CN.md`,
              });
            }