'use strict';

function parseBranchHeader(line, branch) {
  if (line.startsWith('# branch.oid ')) branch.oid = line.slice(13).trim();
  if (line.startsWith('# branch.head ')) branch.head = line.slice(14).trim();
  if (line.startsWith('# branch.upstream ')) branch.upstream = line.slice(18).trim();
  if (line.startsWith('# branch.ab ')) {
    const match = line.match(/\+(\d+)\s+-(\d+)/);
    if (match) {
      branch.ahead = Number(match[1]);
      branch.behind = Number(match[2]);
    }
  }
}

function statusLabel(code) {
  const map = {
    M: 'modified', A: 'added', D: 'deleted', R: 'renamed', C: 'copied',
    U: 'conflict', T: 'type-changed', '?': 'untracked', '!': 'ignored', '.': 'clean', ' ': 'clean'
  };
  return map[code] || 'changed';
}

function buildFile(path, originalPath, xy, kind) {
  const indexCode = xy?.[0] || '.';
  const worktreeCode = xy?.[1] || '.';
  const conflict = kind === 'u' || indexCode === 'U' || worktreeCode === 'U';
  const untracked = kind === '?';
  return {
    path,
    originalPath: originalPath || null,
    indexCode,
    worktreeCode,
    staged: !untracked && indexCode !== '.' && indexCode !== ' ',
    unstaged: untracked || (worktreeCode !== '.' && worktreeCode !== ' '),
    untracked,
    conflict,
    status: conflict ? 'conflict' : untracked ? 'untracked' : statusLabel(worktreeCode !== '.' ? worktreeCode : indexCode)
  };
}

function parsePorcelainV2(output) {
  const branch = { oid: null, head: null, upstream: null, ahead: 0, behind: 0 };
  const files = [];
  const entries = String(output || '').split('\0');

  for (let index = 0; index < entries.length; index += 1) {
    const entry = entries[index];
    if (!entry) continue;
    if (entry.startsWith('# ')) {
      parseBranchHeader(entry, branch);
      continue;
    }

    const kind = entry[0];
    if (kind === '1') {
      const parts = entry.split(' ');
      const xy = parts[1];
      const path = parts.slice(8).join(' ');
      files.push(buildFile(path, null, xy, kind));
    } else if (kind === '2') {
      const parts = entry.split(' ');
      const xy = parts[1];
      const path = parts.slice(9).join(' ');
      const originalPath = entries[index + 1] || null;
      index += 1;
      files.push(buildFile(path, originalPath, xy, kind));
    } else if (kind === 'u') {
      const parts = entry.split(' ');
      const xy = parts[1];
      const path = parts.slice(10).join(' ');
      files.push(buildFile(path, null, xy, kind));
    } else if (kind === '?' || kind === '!') {
      const path = entry.slice(2);
      if (kind === '?') files.push(buildFile(path, null, '??', kind));
    }
  }

  return {
    branch,
    files,
    counts: {
      changed: files.length,
      staged: files.filter((file) => file.staged).length,
      unstaged: files.filter((file) => file.unstaged).length,
      conflicts: files.filter((file) => file.conflict).length,
      untracked: files.filter((file) => file.untracked).length
    },
    clean: files.length === 0
  };
}

module.exports = { parsePorcelainV2, statusLabel };