#!/usr/bin/env python3

import copy
import json
import glob
import os
import sys


def levenshteinDistance(s1, s2):
    if len(s1) > len(s2):
        s1, s2 = s2, s1

    distances = range(len(s1) + 1)
    for i2, c2 in enumerate(s2):
        distances_ = [i2 + 1]
        for i1, c1 in enumerate(s1):
            if c1 == c2:
                distances_.append(distances[i1])
            else:
                distances_.append(
                    1 + min((distances[i1], distances[i1 + 1], distances_[-1]))
                )
        distances = distances_
    return distances[-1]


def Read():
    with open("compile_commands.json") as file:
        return json.load(file)


def Write(compile_commands):
    with open("compile_commands.json", "w") as file:
        json.dump(compile_commands, file, sort_keys=True, indent=2)


def Headers():
    # return [f for f in os.listdir('src') if f.endswith('.h')]
    return glob.glob(os.path.join(os.getcwd(), "src/*.h"))


def NeedsConfigH(header):
    """Returns True if header needs config.h to function"""
    if header.endswith("/config.h"):
        return False
    with open(header) as file:
        return "INLINE_HEADER_BEGIN" in file.read()


def FindSimilarCommand(compile_commands, header):
    header = os.path.join(os.getcwd(), header)
    bestDistance = sys.maxsize
    bestCommand = None
    for command in compile_commands:
        distance = levenshteinDistance(header, command["file"])
        if distance < bestDistance:
            bestDistance = distance
            bestCommand = command
    return bestCommand


def AdaptTemplate(command, header):
    command = copy.deepcopy(command)
    if "output" in command:
        del command["output"]
    src = os.path.relpath(command["file"], command["directory"])
    index = command["arguments"].index(src)
    new_src = os.path.relpath(header, command["directory"])
    command["arguments"][index : index + 1] = [
        "-Wno-unused-macros",
        "-include",
        "config.h",
        new_src,
    ]
    command["file"] = header
    return command


compile_commands = Read()
new_compile_commands = copy.copy(compile_commands)
for header in Headers():
    if NeedsConfigH(header):
        similar = FindSimilarCommand(compile_commands, header)
        if similar["file"] == header:
            continue
        adapted = AdaptTemplate(similar, header)
        new_compile_commands.append(adapted)
Write(new_compile_commands)