#!/usr/bin/env python3
"""把反编译源码里的混淆动态派发还原成真实方法名。

编辑器里几乎每个调用都被编译成 invokedynamic，反编译出来长这样：
    yf_2.OB("lKRXTTGf", "<密文>", "Find")
其中 "lKRXTTGf" 是混淆名，Ob/OB/Nb/HW… 是每个类各自的引导方法。
obmap.tsv 给出了每个混淆名真正指向的方法，于是：
    yf_2.OB("lKRXTTGf", "<密文>", "Find")   ->   java.lang.String.contains("Find")

实例方法统一写成 类名.方法(接收者, 参数...) 的静态形式 —— 不做参数搬移，
这样永远不会解析错参数边界，读起来照样一目了然。

用法：rewrite_source.py <反编译目录> <obmap.tsv> <输出目录>
"""

import os
import re
import sys

# X.bsm("混淆名", "<密文>",  <- 只吃掉这一段
CALL = re.compile(
    r'([A-Za-z_$][\w$]*)\.([A-Za-z_$][\w$]*)\(\s*"([A-Za-z0-9_$]+)"\s*,\s*"(?:[^"\\]|\\.)*"\s*(?:,\s*)?'
)


def load_map(path):
    mapping = {}
    with open(path, encoding="utf-8") as handle:
        for line in handle:
            parts = line.rstrip("\n").split("\t")
            if len(parts) < 4:
                continue
            name, target = parts[2], parts[3]
            if target.startswith("<失败>") or target.startswith("?"):
                continue
            target = target.replace(" (static)", "")
            mapping.setdefault(name, target)
    return mapping


def main():
    source_dir, map_path, out_dir = sys.argv[1], sys.argv[2], sys.argv[3]
    mapping = load_map(map_path)
    print("映射条目 %d" % len(mapping))

    files = replaced_total = files_touched = 0
    missed = set()
    for root, _, names in os.walk(source_dir):
        for name in names:
            if not name.endswith(".java"):
                continue
            files += 1
            path = os.path.join(root, name)
            with open(path, encoding="utf-8", errors="replace") as handle:
                text = handle.read()

            count = [0]

            def swap(match):
                target = mapping.get(match.group(3))
                if target is None:
                    missed.add(match.group(3))
                    return match.group(0)
                count[0] += 1
                return target + "("

            new_text = CALL.sub(swap, text)
            if count[0]:
                files_touched += 1
                replaced_total += count[0]
            relative = os.path.relpath(path, source_dir)
            destination = os.path.join(out_dir, relative)
            os.makedirs(os.path.dirname(destination), exist_ok=True)
            with open(destination, "w", encoding="utf-8") as handle:
                handle.write(new_text)

    print("扫描 %d 个文件，改写 %d 个文件，替换 %d 处调用" % (files, files_touched, replaced_total))
    print("没映射上的混淆名 %d 个" % len(missed))


if __name__ == "__main__":
    main()