#!/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:
# - excludelist mechanism, so a warning is either fixed or excluded
# - 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
import argparse
import pathlib


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

    # Avoid replacing .hpp with .hdl in the com::sun::star and  ooo::vba namespaces.
    if ( include.startswith("com/sun/star") or include.startswith("ooo/vba") ) 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", "debug/multimap.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/shared_ptr.hpp" and "boost/smart_ptr/shared_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
    if include == "boost/functional/hash.hpp" and "boost/container_hash/extensions.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
    if include == "libetonyek/libetonyek.h" and "libetonyek/EtonyekDocument.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",
        # Removing this would change the meaning of '#if defined OSL_BIGENDIAN'.
        "osl/endian.h",
    )
    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, except when --noexclude is given

    if "excludelist" in moduleRules.keys() and not noexclude:
        excludelistRules = moduleRules["excludelist"]
        if fileName in excludelistRules.keys():
            if include in excludelistRules[fileName]:
                return True

    return False


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


def processIWYUOutput(iwyuOutput, moduleRules, fileName, noexclude):
    inAdd = False
    toAdd = []
    inRemove = False
    toRemove = []
    currentFileName = None

    for line in iwyuOutput:
        line = line.strip()

        # Bail out if IWYU gave an error due to non self-containedness
        if re.match ("(.*): error: (.*)", line):
            return -1

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

        shouldAdd = fileName + " should add these lines:"
        match = re.match(shouldAdd, line)
        if match:
            currentFileName = match.group(0).split(' ')[0]
            inAdd = True
            continue

        shouldRemove = fileName + " should remove these lines:"
        match = re.match(shouldRemove, line)
        if match:
            currentFileName = match.group(0).split(' ')[0]
            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:
                # Only suggest removals for now. Removing fwd decls is more complex: they may be
                # indeed unused or they may removed to be replaced with an include. And we want to
                # avoid the later.
                include = unwrapInclude(match.group(1))
                lineno = match.group(2)
                if not ignoreRemoval(include, toAdd, currentFileName, moduleRules, noexclude):
                    toRemove.append("%s:%s: %s" % (currentFileName, lineno, include))

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


def run_tool(task_queue, failed_files, dontstop, noexclude):
    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, invocation.split(' ')[-1], noexclude)
            if retcode == -1:
                print("ERROR: A file is probably not self contained, check this commands output:\n" + invocation)
            elif retcode > 0:
                print("ERROR: The following command found unused includes:\n" + invocation)
                if not dontstop:
                    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, dontstop, noexclude):
    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, dontstop, noexclude))
            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.full_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):
                # Only use assume-filename for headers, so we don't try to analyze e.g. Windows-only
                # code on Linux.
                if "assumeFilename" in moduleRules.keys() and not path.endswith("cxx"):
                    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 -Xiwyu --no_fwd_decls -Xiwyu --max_line_length=200 " + 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):
    parser = argparse.ArgumentParser(description='Check source files for unneeded includes.')
    parser.add_argument('--continue', action='store_true',
                    help='Don\'t stop on errors. Useful for periodic re-check of large amount of files')
    parser.add_argument('Files' , nargs='*',
                    help='The files to be checked')
    parser.add_argument('--recursive', metavar='DIR', nargs=1, type=str,
                    help='Recursively search a directory for source files to check')
    parser.add_argument('--headers', action='store_true',
                    help='Check header files. If omitted, check source files. Use with --recursive.')
    parser.add_argument('--noexclude', action='store_true',
                    help='Ignore excludelist. Useful to check whether its exclusions are still all valid.')

    args = parser.parse_args()

    if not len(argv):
        parser.print_help()
        return

    list_of_files = []
    if args.recursive:
        for root, dirs, files in os.walk(args.recursive[0]):
            for file in files:
                if args.headers:
                    if (file.endswith(".hxx") or file.endswith(".hrc") or file.endswith(".h")):
                        list_of_files.append(os.path.join(root,file))
                else:
                    if (file.endswith(".cxx") or file.endswith(".c")):
                        list_of_files.append(os.path.join(root,file))
    else:
        list_of_files = args.Files

    try:
        with open("compile_commands.json", 'r') as compileCommandsSock:
            compileCommands = json.load(compileCommandsSock)
    except FileNotFoundError:
        print ("File 'compile_commands.json' does not exist, please run:\nmake vim-ide-integration")
        sys.exit(-1)

    # quickly sanity check whether files with exceptions in yaml still exists
    # only check for the module of the very first filename passed

    # Verify there are files selected for checking, with --recursive it
    # may happen that there are in fact no C/C++ files in a module directory
    if not list_of_files:
        print("No files found to check!")
        sys.exit(-2)

    moduleName = sorted(list_of_files)[0].split("/")[0]
    rulePath = os.path.join(moduleName, "IwyuFilter_" + moduleName + ".yaml")
    moduleRules = {}
    if os.path.exists(rulePath):
        moduleRules = yaml.full_load(open(rulePath))
    if "excludelist" in moduleRules.keys():
        excludelistRules = moduleRules["excludelist"]
        for pathname in excludelistRules.keys():
            file = pathlib.Path(pathname)
            if not file.exists():
                print("WARNING: File listed in " + rulePath + " no longer exists: " + pathname)

    tidy(compileCommands, paths=list_of_files, dontstop=vars(args)["continue"], noexclude=args.noexclude)

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

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