#!/usr/bin/env python3
# Copyright 2017 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Checks for incomplete direct deps."""

import argparse
import collections
import logging
import pathlib
import shlex
import sys
from typing import Dict, List, Optional, Set, Tuple

from util import build_utils
from util import dep_utils
from util import jar_utils
from util import server_utils
import action_helpers  # build_utils adds //build to sys.path.


def _ShouldIgnoreDep(dep_name: str):
    if 'gen.base_module.R' in dep_name:
        return True
    return False


def _ParseDepGraph(jar_path: str):
    output = jar_utils.run_jdeps(pathlib.Path(jar_path))
    assert output is not None, f'Unable to parse jdep for {jar_path}'
    dep_graph = collections.defaultdict(set)
    # pylint: disable=line-too-long
    # Example output:
    # java.javac.jar -> java.base
    # java.javac.jar -> not found
    #    org.chromium.chrome.browser.tabmodel.AsyncTabParamsManagerFactory -> java.lang.Object java.base
    #    org.chromium.chrome.browser.tabmodel.TabWindowManagerImpl -> org.chromium.base.ApplicationStatus not found
    #    org.chromium.chrome.browser.tabmodel.TabWindowManagerImpl -> org.chromium.base.ApplicationStatus$ActivityStateListener not found
    #    org.chromium.chrome.browser.tabmodel.TabWindowManagerImpl -> org.chromium.chrome.browser.tab.Tab not found
    # pylint: enable=line-too-long
    for line in output.splitlines():
        parsed = line.split()
        # E.g. java.javac.jar -> java.base
        if len(parsed) <= 3:
            continue
        # E.g. java.javac.jar -> not found
        if parsed[2] == 'not' and parsed[3] == 'found':
            continue
        if parsed[1] != '->':
            continue
        dep_from = parsed[0]
        dep_to = parsed[2]
        dep_graph[dep_from].add(dep_to)
    return dep_graph


def _EnsureDirectClasspathIsComplete(
    *,
    input_jar: str,
    gn_target: str,
    output_dir: str,
    sdk_classpath_jars: List[str],
    direct_classpath_jars: List[str],
    full_classpath_jars: List[str],
    full_classpath_gn_targets: List[str],
    warnings_as_errors: bool,
):
    logging.info('Parsing %d direct classpath jars', len(sdk_classpath_jars))
    sdk_classpath_deps = set()
    for jar in sdk_classpath_jars:
        deps = jar_utils.extract_full_class_names_from_jar(jar)
        sdk_classpath_deps.update(deps)

    logging.info('Parsing %d direct classpath jars', len(direct_classpath_jars))
    direct_classpath_deps = set()
    for jar in direct_classpath_jars:
        deps = jar_utils.extract_full_class_names_from_jar(jar)
        direct_classpath_deps.update(deps)

    logging.info('Parsing %d full classpath jars', len(full_classpath_jars))
    full_classpath_deps = set()
    dep_to_target = collections.defaultdict(set)
    for jar, target in zip(full_classpath_jars, full_classpath_gn_targets):
        deps = jar_utils.extract_full_class_names_from_jar(jar)
        full_classpath_deps.update(deps)
        for dep in deps:
            dep_to_target[dep].add(target)

    transitive_deps = full_classpath_deps - direct_classpath_deps

    missing_class_to_caller: Dict[str, str] = {}
    dep_graph = _ParseDepGraph(input_jar)
    logging.info('Finding missing deps from %d classes', len(dep_graph))
    # dep_graph.keys() is a list of all the classes in the current input_jar. Skip
    # all of these to avoid checking dependencies in the same target (e.g. A
    # depends on B, but both A and B are in input_jar).
    # Since the bundle will always have access to classes in the current android
    # sdk, those should not be considered missing.
    seen_deps = set(dep_graph.keys()) | sdk_classpath_deps
    for dep_from, deps_to in dep_graph.items():
        for dep_to in deps_to - seen_deps:
            if _ShouldIgnoreDep(dep_to):
                continue
            seen_deps.add(dep_to)
            if dep_to in transitive_deps:
                # Allow clobbering since it doesn't matter which specific class depends
                # on |dep_to|.
                missing_class_to_caller[dep_to] = dep_from

    if missing_class_to_caller:
        _ProcessMissingDirectClasspathDeps(
            missing_class_to_caller,
            dep_to_target,
            gn_target,
            output_dir,
            warnings_as_errors,
        )


def _ProcessMissingDirectClasspathDeps(
    missing_class_to_caller: Dict[str, str],
    dep_to_target: Dict[str, Set[str]],
    gn_target: str,
    output_dir: str,
    warnings_as_errors: bool,
):
    potential_targets_to_missing_classes: Dict[Tuple, List[str]] = (
        collections.defaultdict(list)
    )
    for missing_class in missing_class_to_caller:
        potential_targets = tuple(sorted(dep_to_target[missing_class]))
        potential_targets_to_missing_classes[potential_targets].append(
            missing_class
        )

    deps_to_add_programatically = _DisambiguateMissingDeps(
        potential_targets_to_missing_classes, output_dir=output_dir
    )

    cmd = dep_utils.CreateAddDepsCommand(
        gn_target, sorted(deps_to_add_programatically)
    )

    _PrintAndMaybeExit(
        potential_targets_to_missing_classes,
        missing_class_to_caller,
        gn_target,
        warnings_as_errors,
        cmd,
    )


def _DisambiguateMissingDeps(
    potential_targets_to_missing_classes: Dict[Tuple, List[str]],
    output_dir: str,
):
    deps_to_add_programatically = set()
    class_lookup_index = None
    # Run this even when len(potential_targets) == 1, because we need to look for
    # java_group()s with preferred_deps=true.
    for (
        potential_targets,
        missing_classes,
    ) in potential_targets_to_missing_classes.items():
        # Dict for ordered dict.
        potential_targets_dict = {t: True for t in potential_targets}
        # Rather than just picking any of the potential targets, we want to use
        # dep_utils.ClassLookupIndex to ensure we respect the preferred dep if any
        # exists for the missing deps. It is necessary to obtain the preferred dep
        # status of these potential targets by matching them to a ClassEntry.
        target_name_to_class_entry: Dict[str, dep_utils.ClassEntry] = {}
        for missing_class in missing_classes:
            # Lazily create the ClassLookupIndex in case all potential_targets lists
            # are only 1 element in length.
            if class_lookup_index is None:
                class_lookup_index = dep_utils.ClassLookupIndex(
                    pathlib.Path(output_dir), should_build=False
                )
            for class_entry in class_lookup_index.match(missing_class):
                target_name_to_class_entry[class_entry.target] = class_entry
                # Ensure preferred deps are always included in the options.
                if (
                    class_entry.preferred_dep
                    and class_entry.target not in potential_targets_dict
                ):
                    potential_targets_dict[class_entry.target] = True
        potential_class_entries = [
            target_name_to_class_entry[t]
            for t in potential_targets_dict
            if t in target_name_to_class_entry
        ]
        potential_class_entries = dep_utils.DisambiguateDeps(
            potential_class_entries
        )
        if potential_class_entries:
            deps_to_add_programatically.add(potential_class_entries[0].target)
        else:
            # For some missing classes like R.java, the actual file is not in the
            # ClassLookupIndex as it's not listed in the target's sources file. In
            # these corner cases, we can just go with whatever jdeps found as a
            # potential target. See https://crbug.com/437121440 for context.
            deps_to_add_programatically.add(potential_targets[0])
    return deps_to_add_programatically


def _PrintAndMaybeExit(
    potential_targets_to_missing_classes: Dict[Tuple, List[str]],
    missing_class_to_caller: Dict[str, str],
    gn_target: str,
    warnings_as_errors: bool,
    cmd: Optional[List[str]] = None,
):
    print('=' * 30 + ' Dependency Checks Failed ' + '=' * 30)
    print(f'Target: {gn_target}')
    print('Direct classpath is incomplete. To fix, add deps on:')
    for (
        potential_targets,
        missing_classes,
    ) in potential_targets_to_missing_classes.items():
        if len(potential_targets) == 1:
            print(f' * {potential_targets[0]}')
        else:
            print(f' * One of {", ".join(potential_targets)}')
        for missing_class in missing_classes:
            caller = missing_class_to_caller[missing_class]
            print(f'     ** {missing_class} (needed by {caller})')
    if cmd:
        print('\nHint: Run the following command to add the missing deps:')
        print(f'    {shlex.join(cmd)}\n')
    if warnings_as_errors:
        sys.exit(1)


def main(argv):
    build_utils.InitLogging('MISSING_DEPS_DEBUG')
    argv = build_utils.ExpandFileArgs(argv[1:])
    parser = argparse.ArgumentParser()
    parser.add_argument('--target-name', help='Fully qualified GN target name.')
    parser.add_argument(
        '--use-build-server',
        action='store_true',
        help='Always use the build server.',
    )
    parser.add_argument('--gn-target', required=True)
    parser.add_argument('--input-jar', required=True)
    parser.add_argument('--direct-classpath-jars', action='append')
    parser.add_argument('--sdk-classpath-jars')
    parser.add_argument('--full-classpath-jars')
    parser.add_argument('--full-classpath-gn-targets')
    parser.add_argument('--chromium-output-dir')
    parser.add_argument('--depfile')
    parser.add_argument('--stamp')
    parser.add_argument(
        '--warnings-as-errors',
        action='store_true',
        help='Treat all warnings as errors.',
    )
    args = parser.parse_args(argv)

    args.sdk_classpath_jars = action_helpers.parse_gn_list(
        args.sdk_classpath_jars
    )
    args.direct_classpath_jars = action_helpers.parse_gn_list(
        args.direct_classpath_jars
    )
    args.full_classpath_jars = action_helpers.parse_gn_list(
        args.full_classpath_jars
    )
    args.full_classpath_gn_targets = [
        dep_utils.ReplaceGmsPackageIfNeeded(t)
        for t in action_helpers.parse_gn_list(args.full_classpath_gn_targets)
    ]

    # No need to rebuild if full_classpath_jars change and direct_classpath_jars
    # do not.
    depfile_deps = args.direct_classpath_jars + args.sdk_classpath_jars
    action_helpers.write_depfile(args.depfile, args.stamp, depfile_deps)

    if server_utils.MaybeRunCommand(
        name=args.target_name,
        argv=sys.argv,
        stamp_file=args.stamp,
        use_build_server=args.use_build_server,
    ):
        return

    logging.info(
        'Processed args for %s, starting direct classpath check.',
        args.target_name,
    )
    _EnsureDirectClasspathIsComplete(
        input_jar=args.input_jar,
        gn_target=args.gn_target,
        output_dir=args.chromium_output_dir,
        sdk_classpath_jars=args.sdk_classpath_jars,
        direct_classpath_jars=args.direct_classpath_jars,
        full_classpath_jars=args.full_classpath_jars,
        full_classpath_gn_targets=args.full_classpath_gn_targets,
        warnings_as_errors=args.warnings_as_errors,
    )
    logging.info('Check completed.')

    server_utils.MaybeTouch(args.stamp)


if __name__ == '__main__':
    sys.exit(main(sys.argv))