#!/usr/bin/env python

import os
import sys
import json
import argparse
import re
import shlex
import StringIO
import glob
import itertools


SUPPORTED_COMPILERS = [
    "clang",
    "clang\+\+",
    "llvm-cpp-4.2",
    "llvm-g\+\+",
    "llvm-g\+\+-4.2",
    "llvm-gcc",
    "llvm-gcc-4.2",
    "arm-apple-darwin10-llvm-g\+\+-4.2",
    "arm-apple-darwin10-llvm-gcc-4.2",
    "i686-apple-darwin10-llvm-g\+\+-4.2",
    "i686-apple-darwin10-llvm-gcc-4.2",
    "gcc",
    "g\+\+",
    "c\+\+",
    "cc"
]

DEFAULT_INPUT_FILE = "xcodebuild.log"

JSON_COMPILATION_DATABASE = "compile_commands.json"


_find_unsafe = re.compile('[ "\\\\]').search

def clang_quote(s):
    """
    Return a minimally-escaped version of the string *s* that clang-based tools understand.
    (See http://clang.llvm.org/docs/JSONCompilationDatabase.html)
    ex:
      clang_quote('aa') == r'aa'
      clang_quote('a"a') == r'"a\"a"'
      clang_quote('--my-option=a"a') == r'"--my-option=a\"a"'
    """
    if not s:
        return '""'

    if _find_unsafe(s) is None:
        return s

    return '"' + s.replace('\\', '\\\\').replace('"', '\\"') + '"'


_find_quoting = re.compile('[\'"\\\\]').search

def tokenize_command(c):
    """Compute the list of shell arguments in *c* using shlex.split (note: make an explicit call to StringIO for compatibility with Python 2)."""
    if _find_quoting(c) is None:
        return map(str.strip, c.strip().split(' '))
    else:
        return shlex.split(StringIO.StringIO(c))

# global table to map pth files to (source) pch files
_pch_dictionary = {}

def register_source_for_pth_file(clang_command, directory):
    tokens = iter(tokenize_command(clang_command))
    src_file = ""
    pth_file = ""
    try:
        while 1:
            tok = tokens.next()
            if tok == '-c':
                file = tokens.next()
                src_file = file
            elif tok == '-o':
                file = tokens.next()
                if file.endswith('.pch.pth') or file.endswith('.pch.pch'):
                    pth_file = file
    except StopIteration:
        if src_file and pth_file:
            _pch_dictionary[pth_file] = src_file

def get_source_for_pth_file(file):
    src_file = _pch_dictionary.get(file + '.pth')
    if src_file is not None:
        return src_file
    return _pch_dictionary.get(file + '.pch')

def process_clang_command(clang_command, directory):
    tokens = iter(tokenize_command(clang_command))
    command = []
    source_file = None

    try:
        while 1:
            tok = tokens.next()
            if tok == '-include':
                include_file = tokens.next()
                if not os.path.isfile(include_file):
                    src_file = get_source_for_pth_file(include_file)
                    if src_file is not None:
                        include_file = src_file
                    else:
                        print "cannot find original pch source file for %s" % include_file
                        exit(3)
                command.append(tok)
                command.append(clang_quote(include_file))

            elif tok == '-c':
                source_file = tokens.next()
                command.append(tok)
                command.append(clang_quote(source_file))

            else:
                command.append(clang_quote(tok))

    except StopIteration:
        return {"directory": directory, "command": " ".join(command), "file": os.path.normpath(source_file)}


def read_directory(line):
    tokens = tokenize_command(line)
    if tokens[0] == "cd":
        return tokens[1]
    else:
        return ""

def convert(input_file, output_file, is_excluded=None):
    json_input_mode = input_file.endswith('.json')

    find_compileC = re.compile("CompileC").search

    find_processPCH = re.compile("ProcessPCH").search

    find_clang_command = re.compile("(" + "|".join(SUPPORTED_COMPILERS) + ") .* -c .* -o ").search

    if is_excluded is None:
        is_excluded = (lambda x: False)

    with open(output_file, "w") as output:
        with open(input_file, "r") as input:
            if json_input_mode:
                lines = itertools.chain(*(json.loads(line).get('command', '').encode("utf8").splitlines(True) for line in input))
            else:
                lines = input
            try:
                output.write("[")
                cr = "\n"
                while 1:
                    log_line = lines.next()
                    compilation_section_re = find_compileC(log_line)
                    if compilation_section_re:
                        directory = read_directory(lines.next())
                        if is_excluded(directory):
                            continue
                        while 1:
                            log_line = lines.next()
                            if not find_clang_command(log_line):
                                continue
                            output_record = process_clang_command(log_line, directory)
                            output.write(cr)
                            output.write(json.dumps(output_record, indent=2))
                            cr = ",\n"
                            break
                        continue
                    compilation_section_re = find_processPCH(log_line)
                    if compilation_section_re:
                        directory = read_directory(lines.next())
                        if is_excluded(directory):
                            continue
                        while 1:
                            log_line = lines.next()
                            if not find_clang_command(log_line):
                                continue
                            register_source_for_pth_file(log_line, directory)
                            break
                        continue
            except StopIteration:
                output.write("\n]\n");

def main():
    arg_parser = argparse.ArgumentParser(description='Converts xcodebuild logs or xctool-json-reporter logs to compile_commands.json')
    arg_parser.add_argument("-e", "-exclude", dest="exclusion", help="Directory exclusion pattern (regular expression)")
    arg_parser.add_argument("-o", "-output", dest="output_file", help="Output json file (default: ./%s)" % JSON_COMPILATION_DATABASE)
    arg_parser.add_argument(metavar="FILE", nargs='?', dest="input_file", help="Input log file (default: ./%s)" % DEFAULT_INPUT_FILE)

    args = arg_parser.parse_args()

    if args.input_file:
        input_file = args.input_file
    else:
        input_file = DEFAULT_INPUT_FILE

    if args.output_file:
        output_file = args.output_file
    else:
        output_file = JSON_COMPILATION_DATABASE

    if not os.path.isfile(input_file):
        print "Error: %s not found." % input_file
        exit(1)

    if args.exclusion:
        is_excluded = re.compile(args.exclusion).match
    else:
        is_excluded = None

    convert(input_file, output_file, is_excluded)


if __name__ == '__main__':
    main()