#!/usr/bin/env python3
"""Diff two javap dumps produced by dump_api.py and report changes to PUBLIC API only.

usage: apidiff.py <old-dump> <new-dump> [--vector-only]

A class is reported only if its declaration starts with 'public' in the old or the new dump, so
package-private implementation classes (which javap -public still lists) do not drown the signal.
"""
import collections
import re
import sys


def parse(path):
    classes = collections.OrderedDict()
    decl = {}
    cur = None
    for line in open(path):
        line = line.rstrip("\n")
        if line.startswith("#####") or line.startswith("Compiled from") or not line.strip():
            continue
        if not line.startswith(" "):
            m = re.search(r"(?:class|interface|enum|@interface|record)\s+([\w.$]+)", line)
            cur = m.group(1) if m else line
            classes[cur] = set()
            decl[cur] = line
        elif cur is not None and line.strip() != "}":
            classes[cur].add(line.strip())
    return classes, decl


def is_public(decl_line):
    return decl_line.startswith("public ") or decl_line.startswith("protected ")


def main():
    old, old_decl = parse(sys.argv[1])
    new, new_decl = parse(sys.argv[2])
    vector_only = "--vector-only" in sys.argv

    def keep(name):
        if vector_only and not name.startswith("jdk.incubator.vector."):
            return False
        if name.startswith("file") or "Error: Access Flags" in old_decl.get(name, "") + new_decl.get(name, ""):
            return False
        return is_public(old_decl.get(name, "")) or is_public(new_decl.get(name, ""))

    print("## public classes removed")
    for c in sorted(set(old) - set(new)):
        if keep(c):
            print("  " + c)
    print("## public classes added")
    for c in sorted(set(new) - set(old)):
        if keep(c):
            print("  " + c)
    print("## public class changes")
    for c in sorted(set(old) & set(new)):
        if not keep(c):
            continue
        removed = old[c] - new[c]
        added = new[c] - old[c]
        d_old, d_new = old_decl[c], new_decl[c]
        if removed or added or d_old != d_new:
            print(c)
            if d_old != d_new:
                print("   - " + d_old.strip())
                print("   + " + d_new.strip())
            for x in sorted(removed):
                print("   - " + x)
            for x in sorted(added):
                print("   + " + x)


main()