#!/usr/bin/env python3
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# This parses the output of 'include-what-you-use', focusing on just removing
# not needed includes and providing a relatively conservative output by
# filtering out a number of LibreOffice-specific false positives.
#
# It assumes you have a 'compile_commands.json' around (similar to clang-tidy),
# you can generate one with 'make vim-ide-integration'.
#
# Design goals:
# - blacklist mechanism, so a warning is either fixed or blacklisted
# - works in a plugins-enabled clang build
# - no custom configure options required
# - no need to generate a dummy library to build a header

import glob
import json
import multiprocessing
import os
import queue
import re
import subprocess
import sys
import threading
import yaml


def ignoreRemoval(include, toAdd, absFileName, moduleRules):
    # global rules

    # Avoid replacing .hpp with .hdl in the com::sun::star namespace.
    if include.startswith("com/sun/star") and include.endswith(".hpp"):
        hdl = include.replace(".hpp", ".hdl")
        if hdl in toAdd:
            return True

    # Avoid debug STL.
    debugStl = {
        "array": ("debug/array", ),
        "bitset": ("debug/bitset", ),
        "deque": ("debug/deque", ),
        "forward_list": ("debug/forward_list", ),
        "list": ("debug/list", ),
        "map": ("debug/map.h", ),
        "set": ("debug/set.h", "debug/multiset.h"),
        "unordered_map": ("debug/unordered_map", ),
        "unordered_set": ("debug/unordered_set", ),
        "vector": ("debug/vector", ),
    }
    for k, values in debugStl.items():
        if include == k:
            for value in values:
                if value in toAdd:
                    return True

    # Avoid proposing to use libstdc++ internal headers.
    bits = {
        "exception": "bits/exception.h",
        "memory": "bits/shared_ptr.h",
        "functional": "bits/std_function.h",
        "cmath": "bits/std_abs.h",
        "ctime": "bits/types/clock_t.h",
        "cstdint": "bits/stdint-uintn.h"
    }
    for k, v in bits.items():
        if include == k and v in toAdd:
            return True

    # Avoid proposing o3tl fw declaration
    o3tl = {
        "o3tl/typed_flags_set.hxx" : "namespace o3tl { template <typename T> struct typed_flags; }",
        "o3tl/deleter.hxx" : "namespace o3tl { template <typename T> struct default_delete; }",
        "o3tl/span.hxx" : "namespace o3tl { template <typename T> class span; }",
    }
    for k, v, in o3tl.items():
        if include == k and v in toAdd:
            return True

    # Follow boost documentation.
    if include == "boost/optional.hpp" and "boost/optional/optional.hpp" in toAdd:
        return True
    if include == "boost/intrusive_ptr.hpp" and "boost/smart_ptr/intrusive_ptr.hpp" in toAdd:
        return True
    if include == "boost/variant.hpp" and "boost/variant/variant.hpp" in toAdd:
        return True
    if include == "boost/unordered_map.hpp" and "boost/unordered/unordered_map.hpp" in toAdd:
        return True

    # Avoid .hxx to .h proposals in basic css/uno/* API
    unoapi = {
        "com/sun/star/uno/Any.hxx": "com/sun/star/uno/Any.h",
        "com/sun/star/uno/Reference.hxx": "com/sun/star/uno/Reference.h",
        "com/sun/star/uno/Sequence.hxx": "com/sun/star/uno/Sequence.h",
        "com/sun/star/uno/Type.hxx": "com/sun/star/uno/Type.h"
    }
    for k, v in unoapi.items():
        if include == k and v in toAdd:
            return True

    # 3rd-party, non-self-contained headers.
    if include == "libepubgen/libepubgen.h" and "libepubgen/libepubgen-decls.h" in toAdd:
        return True
    if include == "librevenge/librevenge.h" and "librevenge/RVNGPropertyList.h" in toAdd:
        return True

    noRemove = (
        # <https://www.openoffice.org/tools/CodingGuidelines.sxw> insists on not
        # removing this.
        "sal/config.h",
        # Works around a build breakage specific to the broken Android
        # toolchain.
        "android/compatibility.hxx",
    )
    if include in noRemove:
        return True

    # Ignore when <foo> is to be replaced with "foo".
    if include in toAdd:
        return True

    fileName = os.path.relpath(absFileName, os.getcwd())

    # Skip headers used only for compile test
    if fileName == "cppu/qa/cppumaker/test_cppumaker.cxx":
        if include.endswith(".hpp"):
            return True

    # yaml rules

    if "blacklist" in moduleRules.keys():
        blacklistRules = moduleRules["blacklist"]
        if fileName in blacklistRules.keys():
            if include in blacklistRules[fileName]:
                return True

    return False


def unwrapInclude(include):
    # Drop <> or "" around the include.
    return include[1:-1]


def processIWYUOutput(iwyuOutput, moduleRules):
    inAdd = False
    toAdd = []
    inRemove = False
    toRemove = []
    currentFileName = None
    for line in iwyuOutput:
        line = line.strip()

        if len(line) == 0:
            if inRemove:
                inRemove = False
                continue
            if inAdd:
                inAdd = False
                continue

        match = re.match("(.*) should add these lines:$", line)
        if match:
            currentFileName = match.group(1)
            inAdd = True
            continue

        match = re.match("(.*) should remove these lines:$", line)
        if match:
            currentFileName = match.group(1)
            inRemove = True
            continue

        if inAdd:
            match = re.match('#include ([^ ]+)', line)
            if match:
                include = unwrapInclude(match.group(1))
                toAdd.append(include)
            else:
                # Forward declaration.
                toAdd.append(line)

        if inRemove:
            match = re.match("- #include (.*)  // lines (.*)-.*", line)
            if match:
                include = unwrapInclude(match.group(1))
                lineno = match.group(2)
                if not ignoreRemoval(include, toAdd, currentFileName, moduleRules):
                    toRemove.append("%s:%s: %s" % (currentFileName, lineno, include))
                continue

            match = re.match("- (.*;(?: })*)*  // lines (.*)-.*", line)
            if match:
                fwdDecl = match.group(1)
                if fwdDecl.endswith(";"):
                    # Remove trailing semicolon.
                    fwdDecl = fwdDecl[:-1]
                lineno = match.group(2)
                if not ignoreRemoval(fwdDecl, toAdd, currentFileName, moduleRules):
                    toRemove.append("%s:%s: %s" % (currentFileName, lineno, fwdDecl))

    for remove in sorted(toRemove):
        print("ERROR: %s: remove not needed include / forward declaration" % remove)
    return len(toRemove)


def run_tool(task_queue, failed_files):
    while True:
        invocation, moduleRules = task_queue.get()
        if not len(failed_files):
            print("[IWYU] " + invocation.split(' ')[-1])
            p = subprocess.Popen(invocation, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
            retcode = processIWYUOutput(p.communicate()[0].decode('utf-8').splitlines(), moduleRules)
            if retcode != 0:
                print("ERROR: The following command found unused includes:\n" + invocation)
                failed_files.append(invocation)
        task_queue.task_done()


def isInUnoIncludeFile(path):
    return path.startswith("include/com/") \
            or path.startswith("include/cppu/") \
            or path.startswith("include/cppuhelper/") \
            or path.startswith("include/osl/") \
            or path.startswith("include/rtl/") \
            or path.startswith("include/sal/") \
            or path.startswith("include/salhelper/") \
            or path.startswith("include/systools/") \
            or path.startswith("include/typelib/") \
            or path.startswith("include/uno/")


def tidy(compileCommands, paths):
    return_code = 0
    try:
        max_task = multiprocessing.cpu_count()
        task_queue = queue.Queue(max_task)
        failed_files = []
        for _ in range(max_task):
            t = threading.Thread(target=run_tool, args=(task_queue, failed_files))
            t.daemon = True
            t.start()

        for path in sorted(paths):
            if isInUnoIncludeFile(path):
                continue

            moduleName = path.split("/")[0]

            rulePath = os.path.join(moduleName, "IwyuFilter_" + moduleName + ".yaml")
            moduleRules = {}
            if os.path.exists(rulePath):
                moduleRules = yaml.load(open(rulePath))
            assume = None
            pathAbs = os.path.abspath(path)
            compileFile = pathAbs
            matches = [i for i in compileCommands if i["file"] == compileFile]
            if not len(matches):
                if "assumeFilename" in moduleRules.keys():
                    assume = moduleRules["assumeFilename"]
                if assume:
                    assumeAbs = os.path.abspath(assume)
                    compileFile = assumeAbs
                    matches = [i for i in compileCommands if i["file"] == compileFile]
                    if not len(matches):
                        print("WARNING: no compile commands for '" + path + "' (assumed filename: '" + assume + "'")
                        continue
                else:
                    print("WARNING: no compile commands for '" + path + "'")
                    continue

            _, _, args = matches[0]["command"].partition(" ")
            if assume:
                args = args.replace(assumeAbs, "-x c++ " + pathAbs)

            invocation = "include-what-you-use " + args
            task_queue.put((invocation, moduleRules))

        task_queue.join()
        if len(failed_files):
            return_code = 1

    except KeyboardInterrupt:
        print('\nCtrl-C detected, goodbye.')
        os.kill(0, 9)

    sys.exit(return_code)


def main(argv):
    if not len(argv):
        print("usage: find-unneeded-includes [FILE]...")
        return

    with open("compile_commands.json", 'r') as compileCommandsSock:
        compileCommands = json.load(compileCommandsSock)

    tidy(compileCommands, paths=argv)

if __name__ == '__main__':
    main(sys.argv[1:])

# vim:set shiftwidth=4 softtabstop=4 expandtab: