"""
i18n_rewrite_calls.py - 用 migration-map 自动改所有 $lang 调用

扫描所有 .vue / .js（排除 lang/、node_modules、unpackage、stub-app-projects），
把 $lang('oldKey') / $lang("oldKey") / this.$lang('oldKey') 替换为 $lang('newKey')。

输出：
- docs/i18n-call-rewrite.log（每个改写点）
- docs/i18n-ambiguous.json（同名 oldKey 映射到多个 newKey 的位置，待人工 review）

注意：本脚本只做"机械替换"，不会改 CSS / 模板结构 / 业务文案。
"""
import os
import re
import json
from pathlib import Path
from collections import defaultdict

ROOT = Path(__file__).resolve().parent.parent
MAP_FILE = ROOT / 'lang' / '_migration-map.json'
LOG_FILE = ROOT / 'docs' / 'i18n-call-rewrite.log'
AMBIG_FILE = ROOT / 'docs' / 'i18n-ambiguous.json'

EXCLUDE_DIRS = {'node_modules', 'unpackage', 'stub-app-projects', '.git', 'lang'}
EXCLUDE_FILES_PARTS = {'_migration-map.json', 'i18n-audit.json', 'i18n-strict-audit.json', 'i18n-shadow-audit.json', 'i18n-call-rewrite.log', 'i18n-ambiguous.json'}

# $lang('xxx') / $lang("xxx") / this.$lang('xxx')
CALL_RE = re.compile(r"""((?:this\.)?\$lang)\(\s*(['"])([^'"]+)\2""")


def collect_old_keys():
    """从 migration-map.json 读取 old→new 映射"""
    if not MAP_FILE.exists():
        print(f'[ERROR] {MAP_FILE} 不存在')
        return {}
    data = json.loads(MAP_FILE.read_text(encoding='utf-8'))
    return data.get('old_to_new', {})


def find_target_files():
    """扫描所有需要改写的 .vue / .js"""
    files = []
    for p in ROOT.rglob('*'):
        if not p.is_file():
            continue
        if not (str(p).endswith('.vue') or str(p).endswith('.js')):
            continue
        # 排除目录
        parts = set(p.parts)
        if parts & EXCLUDE_DIRS:
            continue
        # 排除特定文件
        if any(part in EXCLUDE_FILES_PARTS for part in p.name.split('_')):
            continue
        if p.name.startswith('i18n-'):
            continue
        files.append(p)
    return files


def rewrite_file(path, old_to_new, log_lines, ambiguous):
    """改写一个文件，记录所有改动"""
    try:
        text = path.read_text(encoding='utf-8')
    except UnicodeDecodeError:
        return 0
    original = text
    rel = str(path.relative_to(ROOT))
    changes = []

    def repl(m):
        prefix = m.group(1)
        quote = m.group(2)
        old_key = m.group(3)
        if old_key in old_to_new:
            new_key = old_to_new[old_key]
            changes.append((old_key, new_key))
            return f"{prefix}({quote}{new_key}{quote}"
        return m.group(0)

    new_text = CALL_RE.sub(repl, text)

    # 检测 ambiguous: 同一文件里 old_key 被映射到不同 new_key
    # 这里需要从 migration-map 区分
    # 简单办法: 检查 old_key 是否在 old_to_new 里但 new_key 不唯一
    # 由于 migration-map 是 1对1 的扁平 dict（一个 old_key 只对应一个 new_key），
    # 所以 ambiguous 出现在 migration-map 本身（如果未来一个 old key 被映射到多个新 key）

    if new_text != original:
        path.write_text(new_text, encoding='utf-8')
        for old_k, new_k in changes:
            log_lines.append(f'{rel}: $lang("{old_k}") -> $lang("{new_k}")')
        return len(changes)
    return 0


def main():
    import argparse
    parser = argparse.ArgumentParser()
    parser.add_argument('--apply', action='store_true', help='真的改写文件（默认 dry-run）')
    args = parser.parse_args()

    old_to_new = collect_old_keys()
    print(f'共 {len(old_to_new)} 条迁移规则')

    rev = defaultdict(list)
    for old, new in old_to_new.items():
        rev[new].append(old)
    ambiguous_targets = {new: olds for new, olds in rev.items() if len(olds) > 1}
    if ambiguous_targets:
        print(f'发现 {len(ambiguous_targets)} 个新 key 被多个旧 key 指向（ambiguous）')

    files = find_target_files()
    print(f'扫描到 {len(files)} 个文件')

    log_lines = []
    total_changes = 0
    files_changed = 0

    for p in files:
        try:
            text = p.read_text(encoding='utf-8')
        except UnicodeDecodeError:
            continue
        rel = str(p.relative_to(ROOT))
        file_changes = []

        def repl(m, _f=file_changes):
            prefix = m.group(1)
            quote = m.group(2)
            old_key = m.group(3)
            if old_key in old_to_new:
                new_key = old_to_new[old_key]
                _f.append((old_key, new_key))
                return f"{prefix}({quote}{new_key}{quote}"
            return m.group(0)

        new_text = CALL_RE.sub(repl, text)

        if new_text != text:
            file_change_count = len(file_changes)
            total_changes += file_change_count
            files_changed += 1
            for old_k, new_k in file_changes:
                log_lines.append(f'{rel}: $lang("{old_k}") -> $lang("{new_k}")')

            # 仅在 --apply 模式下真正写文件
            if args.apply:
                p.write_text(new_text, encoding='utf-8')

    LOG_FILE.parent.mkdir(exist_ok=True)
    LOG_FILE.write_text('\n'.join(log_lines), encoding='utf-8')
    mode = 'APPLY' if args.apply else 'DRY-RUN'
    print(f'\n[{mode}] 改写日志 -> {LOG_FILE.relative_to(ROOT)}')
    print(f'  拟改写 {total_changes} 处，涉及 {files_changed} 个文件')
    if not args.apply:
        print(f'  -- 未实际修改文件。要应用请加 --apply 参数 --')

    AMBIG_FILE.write_text(json.dumps({
        'ambiguous_new_keys': ambiguous_targets,
        'note': '这些 new_key 被多个 old_key 指向，需要人工 review 决定哪个 old_key 应该映射到哪个 new_key',
    }, ensure_ascii=False, indent=2), encoding='utf-8')
    print(f'[OK] Ambiguous 清单 -> {AMBIG_FILE.relative_to(ROOT)}')


if __name__ == '__main__':
    main()