#!/usr/bin/env python
from __future__ import print_function
from __future__ import absolute_import
from contextlib import contextmanager
import logging
import os
import re
import sys
import optparse
import subprocess
import traceback

try:
    import lister
    from typing import cast, Any, Callable, Dict, List, Optional, Generator, Tuple
except ImportError as e:
    print("ImportError: {}".format(e))
    print("You need to run the Zulip linters inside a Zulip dev environment.")
    print("If you are using Vagrant, you can `vagrant ssh` to enter the Vagrant guest.")
    sys.exit(1)

# Exclude some directories and files from lint checking
EXCLUDED_FILES = """
api/integrations/perforce/git_p4.py
api/setup.py
docs/html_unescape.py
frontend_tests/casperjs
node_modules
puppet/apt/.forge-release
puppet/apt/README.md
static/locale
static/third
tools/jslint/jslint.js
zerver/migrations
zproject/dev_settings.py
zproject/settings.py
zproject/test_settings.py
""".split()

@contextmanager
def bright_red_output():
    # type: () -> Generator[None, None, None]
    # Make the lint output bright red
    sys.stdout.write('\x1B[1;31m')
    sys.stdout.flush()
    try:
        yield
    finally:
        # Restore normal terminal colors
        sys.stdout.write('\x1B[0m')


def check_pyflakes(options, by_lang):
    # type: (Any, Dict[str, List[str]]) -> bool
    if not by_lang['py']:
        return False
    failed = False
    pyflakes = subprocess.Popen(['pyflakes'] + by_lang['py'],
        stdout = subprocess.PIPE,
        stderr = subprocess.PIPE,
        universal_newlines = True)

    # pyflakes writes some output (like syntax errors) to stderr. :/
    for pipe in (pyflakes.stdout, pyflakes.stderr):
        for ln in pipe:
            if options.full or not \
                    ('imported but unused' in ln or
                     'redefinition of unused' in ln or
                     ("zerver/models.py" in ln and
                      " undefined name 'bugdown'" in ln) or
                     ("scripts/lib/pythonrc.py" in ln and
                      " import *' used; unable to detect undefined names" in ln) or
                     ("zerver/lib/tornado_ioloop_logging.py" in ln and
                      "redefinition of function 'instrument_tornado_ioloop'" in ln) or
                     ("zephyr_mirror_backend.py:" in ln and
                      "redefinition of unused 'simplejson' from line" in ln)):
                sys.stdout.write(ln)
                failed = True
    return failed

def run_parallel(lint_functions):
    # type: (Dict[str, Callable[[], int]]) -> bool
    pids = []
    for name, func in lint_functions.items():
        pid = os.fork()
        if pid == 0:
            logging.info("start " + name)
            result = func()
            logging.info("finish " + name)
            sys.stdout.flush()
            sys.stderr.flush()
            os._exit(result)
        pids.append(pid)
    failed = False

    for pid in pids:
        (_, status) = os.waitpid(pid, 0)
        if status != 0:
            failed = True
    return failed

def build_custom_checkers(by_lang):
    # type: (Dict[str, List[str]]) -> Tuple[Callable[[], bool], Callable[[], bool]]
    RuleList = List[Dict[str, Any]]

    def custom_check_file(fn, rules, skip_rules=None, max_length=None):
        # type: (str, RuleList, Optional[Any], Optional[int]) -> bool
        failed = False
        lineFlag = False
        for i, line in enumerate(open(fn)):
            line_newline_stripped = line.strip('\n')
            line_fully_stripped = line_newline_stripped.strip()
            skip = False
            lineFlag = True
            for rule in skip_rules or []:
                if re.match(rule, line):
                    skip = True
            if skip:
                continue
            for rule in rules:
                exclude_list = rule.get('exclude', set())
                if fn in exclude_list:
                    continue
                exclude_list = rule.get('exclude_line', set())
                if (fn, line_fully_stripped) in exclude_list:
                    continue
                try:
                    line_to_check = line_fully_stripped
                    if rule.get('strip') is not None:
                        if rule['strip'] == '\n':
                            line_to_check = line_newline_stripped
                        else:
                            raise Exception("Invalid strip rule")
                    if re.search(rule['pattern'], line_to_check):
                        sys.stdout.write(rule['description'] + ' at %s line %s:\n' % (fn, i+1))
                        print(line)
                        failed = True
                except Exception:
                    print("Exception with %s at %s line %s" % (rule['pattern'], fn, i+1))
                    traceback.print_exc()
            if (max_length is not None and len(line) > max_length and
                '# type' not in line and 'test' not in fn and 'example' not in fn and
                "#ignorelongline" not in line):
                print("Line too long (%s) at %s line %s: %s" % (len(line), fn, i+1, line_newline_stripped))
            lastLine = line
        if lineFlag and '\n' not in lastLine:
            print("No newline at the end of file.  Fix with `sed -i '$a\\' %s`" % (fn,))
            failed = True
        return failed

    whitespace_rules = [
        # This linter should be first since bash_rules depends on it.
        {'pattern': '\s+$',
         'strip': '\n',
         'description': 'Fix trailing whitespace'},
        {'pattern': '\t',
         'strip': '\n',
         'exclude': set(['zerver/lib/bugdown/codehilite.py',
                         'tools/travis/success-http-headers.txt']),
         'description': 'Fix tab-based whitespace'},
        ] # type: RuleList
    markdown_whitespace_rules = list([rule for rule in whitespace_rules if rule['pattern'] != '\s+$']) + [
       # Two spaces trailing a line with other content is okay--it's a markdown line break.
       # This rule finds one space trailing a non-space, three or more trailing spaces, and
       # spaces on an empty line.
       {'pattern': '((?<!\s)\s$)|(\s\s\s+$)|(^\s+$)',
        'strip': '\n',
        'description': 'Fix trailing whitespace'},
       ] # type: RuleList
    js_rules = cast(RuleList, [
        {'pattern': '[^_]function\(',
         'description': 'The keyword "function" should be followed by a space'},
        {'pattern': '.*blueslip.warning\(.*',
         'description': 'The module blueslip has no function warning, try using blueslip.warn'},
        {'pattern': '[)]{$',
         'description': 'Missing space between ) and {'},
        {'pattern': '["\']json/',
         'description': 'Relative URL for JSON route not supported by i18n'},
        # This rule is constructed with + to avoid triggering on itself
        {'pattern': " =" + '[^ =>~"]',
         'description': 'Missing whitespace after "="'},
        {'pattern': '^[ ]*//[A-Za-z0-9]',
         'description': 'Missing space after // in comment'},
        {'pattern': 'if[(]',
         'description': 'Missing space between if and ('},
        {'pattern': 'else{$',
         'description': 'Missing space between else and {'},
        {'pattern': '^else {$',
         'description': 'Write JS else statements on same line as }'},
        {'pattern': '^else if',
         'description': 'Write JS else statements on same line as }'},
        {'pattern': 'button\.text\(["\']',
         'exclude': set(['tools/lint-all',
                         'frontend_tests/node_tests/templates.js']),
         'description': 'Argument to button.text should be a literal string enclosed by i18n.t()'},
        {'pattern': 'compose_error\(["\']',
         'exclude': set(['tools/lint-all']),
         'description': 'Argument to compose_error should be a literal string enclosed '
                        'by i18n.t()'},
        {'pattern': 'report_success\(["\']',
         'exclude': set(['tools/lint-all']),
         'description': 'Argument to report_success should be a literal string enclosed '
                        'by i18n.t()'},
        {'pattern': 'report_error\(["\']',
         'exclude': set(['tools/lint-all']),
         'description': 'Argument to report_error should be a literal string enclosed '
                        'by i18n.t()'},
        ]) + whitespace_rules
    python_rules = cast(RuleList, [
        {'pattern': '^(?!#)@login_required',
         'description': '@login_required is unsupported; use @zulip_login_required'},
        {'pattern': '".*"%\([a-z_].*\)?$',
         'description': 'Missing space around "%"'},
        {'pattern': "'.*'%\([a-z_].*\)?$",
         'exclude': set(['tools/lint-all']),
         'exclude_line': set([
             ('zerver/views/users.py',
              "return json_error(_(\"Email '%(email)s' does not belong to domain '%(domain)s'\") %"),
         ]),
         'description': 'Missing space around "%"'},
        # This rule is constructed with + to avoid triggering on itself
        {'pattern': " =" + '[^ =>~"]',
         'description': 'Missing whitespace after "="'},
        {'pattern': '":\w[^"]*$',
         'description': 'Missing whitespace after ":"'},
        {'pattern': "':\w[^']*$",
         'description': 'Missing whitespace after ":"'},
        {'pattern': "^\s+[#]\w",
         'strip': '\n',
         'description': 'Missing whitespace after "#"'},
        {'pattern': "== None",
         'exclude': 'tools/lint-all',
         'description': 'Use `is None` to check whether something is None'},
        {'pattern': "type:[(]",
         'description': 'Missing whitespace after ":" in type annotation'},
        {'pattern': "# type [(]",
         'description': 'Missing : after type in type annotation'},
        {'pattern': "#type",
         'exclude': 'tools/lint-all',
         'description': 'Missing whitespace after "#" in type annotation'},
        {'pattern': 'if[(]',
         'description': 'Missing space between if and ('},
        {'pattern': ", [)]",
         'description': 'Unnecessary whitespace between "," and ")"'},
        {'pattern': "%  [(]",
         'description': 'Unnecessary whitespace between "%" and "("'},
        # This next check could have false positives, but it seems pretty
        # rare; if we find any, they can be added to the exclude list for
        # this rule.
        {'pattern': '% [a-zA-Z0-9_.]*\)?$',
         'description': 'Used % comprehension without a tuple'},
        # To avoid json_error(_variable) and json_error(_(variable))
        {'pattern': '\Wjson_error\(_\(?\w+\)',
         'exclude': set(['tools/lint-all']),
         'description': 'Argument to json_error should be a literal string enclosed by _()'},
        {'pattern': '\Wjson_error\([^_].+[),]$',
         'exclude': set(['tools/lint-all']),
         'exclude_line': set([
             # function definition
             ('zerver/lib/response.py', 'def json_error(msg, data=None, status=400):'),
             # No need to worry about the following as the translation strings
             # are already captured
             ('zerver/middleware.py',
              'return json_error(exception.to_json_error_msg(), status=status_code)'),
             ('zerver/tornadoviews.py', 'return json_error(result["message"])'),
             ('zerver/views/__init__.py',
              'return json_error(data=error_data, msg=ret_error)'),
             ('zerver/views/streams.py', 'return json_error(property_conversion)'),
             # We can't do anything about this.
             ('zerver/views/realm_emoji.py', 'return json_error(e.messages[0])'),
         ]),
         'description': 'Argument to json_error should a literal string enclosed by _()'},
        # To avoid JsonableError(_variable) and JsonableError(_(variable))
        {'pattern': '\WJsonableError\(_\(?\w.+\)',
         'exclude': set(['tools/lint-all']),
         'description': 'Argument to JsonableError should be a literal string enclosed by _()'},
        {'pattern': '\WJsonableError\([^_].+\)',
         'exclude': set(['tools/lint-all']),
         'exclude_line': set([
             # class definition
             ('zerver/lib/request.py', 'class JsonableError(Exception):'),
             # No need to worry about the following as the translation strings
             # are already captured
             ('zerver/decorator.py', 'raise JsonableError(reason % (role,))'),
             ('zerver/lib/actions.py', 'raise JsonableError(e.messages[0])'),
             ('zerver/views/messages.py', 'raise JsonableError(error)'),
             ('zerver/lib/request.py', 'raise JsonableError(error)'),
         ]),
         'description': 'Argument to JsonableError should be a literal string enclosed by _()'},
        {'pattern': '([a-zA-Z0-9_]+)=REQ\([\'"]\\1[\'"]',
         'description': 'REQ\'s first argument already defaults to parameter name'},
        {'pattern': 'self\.client\.(get|post|patch|put|delete)',
         'exclude': set(['zilencer/tests.py']),
         'description': \
    '''Do not call self.client directly for put/patch/post/get.
    See WRAPPER_COMMENT in test_helpers.py for details.
    '''},

        ]) + whitespace_rules
    bash_rules = [
        {'pattern': '#!.*sh [-xe]',
         'description': 'Fix shebang line with proper call to /usr/bin/env for Bash path, change -x|-e switches'
                        ' to set -x|set -e'},
        ] + whitespace_rules[0:1] # type: RuleList
    css_rules = [
        {'pattern': '^[^:]*:\S[^:]*;$',
         'description': "Missing whitespace after : in CSS"},
        {'pattern': '[a-z]{',
         'description': "Missing whitespace before '{' in CSS."},
        {'pattern': '{\w',
         'description': "Missing whitespace after '{' in CSS (should be newline)."},
        ] + whitespace_rules # type: RuleList
    handlebars_rules = whitespace_rules
    html_rules = whitespace_rules + [
        {'pattern': 'placeholder="[^{]',
         'description': "`placeholder` value should be translatable."},
        {'pattern': "placeholder='[^{]",
         'description': "`placeholder` value should be translatable."},
        ] # type: RuleList
    json_rules = [] # type: RuleList # just fix newlines at ends of files
    markdown_rules = markdown_whitespace_rules + [
        {'pattern': ' [jJ]avascript',
         'exclude': set(['README.dev.md']), # temporary exclusion to avoid merge conflicts
         'description': "javascript should be spelled JavaScript"},
    ] # type: RuleList
    txt_rules = whitespace_rules

    def check_custom_checks_py():
        # type: () -> bool
        failed = False

        for fn in by_lang['py']:
            if custom_check_file(fn, python_rules, max_length=140):
                failed = True
        return failed

    def check_custom_checks_nonpy():
        # type: () -> bool
        failed = False

        for fn in by_lang['js']:
            if custom_check_file(fn, js_rules):
                failed = True

        for fn in by_lang['sh']:
            if custom_check_file(fn, bash_rules):
                failed = True

        for fn in by_lang['css']:
            if custom_check_file(fn, css_rules):
                failed = True

        for fn in by_lang['handlebars']:
            if custom_check_file(fn, handlebars_rules):
                failed = True

        for fn in by_lang['html']:
            if custom_check_file(fn, html_rules):
                failed = True

        for fn in by_lang['json']:
            if custom_check_file(fn, json_rules):
                failed = True

        for fn in by_lang['md']:
            if custom_check_file(fn, markdown_rules):
                failed = True

        for fn in by_lang['txt'] + by_lang['text']:
            if custom_check_file(fn, txt_rules):
                failed = True

        return failed

    return (check_custom_checks_py, check_custom_checks_nonpy)

def run():
    # type: () -> None
    parser = optparse.OptionParser()
    parser.add_option('--full',
        action='store_true',
        help='Check some things we typically ignore')
    parser.add_option('--modified', '-m',
        action='store_true',
        help='Only check modified files')
    parser.add_option('--verbose', '-v',
        action='store_true',
        help='Print verbose timing output')
    (options, args) = parser.parse_args()

    os.chdir(os.path.join(os.path.dirname(__file__), '..'))


    by_lang = cast(Dict[str, List[str]], lister.list_files(args, modified_only=options.modified,
        ftypes=['py', 'sh', 'js', 'pp', 'css', 'handlebars', 'html', 'json', 'md', 'txt', 'text'],
        use_shebang=True, group_by_ftype=True, exclude=EXCLUDED_FILES))

    # Invoke the appropriate lint checker for each language,
    # and also check files for extra whitespace.

    logging.basicConfig(format="%(asctime)s %(message)s")
    logger = logging.getLogger()
    if options.verbose:
        logger.setLevel(logging.INFO)
    else:
        logger.setLevel(logging.WARNING)

    check_custom_checks_py, check_custom_checks_nonpy = build_custom_checkers(by_lang)

    lint_functions = {} # type: Dict[str, Callable[[], int]]

    def lint(func):
        # type: (Callable[[], int]) -> Callable[[], int]
        lint_functions[func.__name__] = func
        return func

    with bright_red_output():
        @lint
        def templates():
            # type: () -> int
            args = ['tools/check-templates']
            if options.modified:
                args.append('-m')
            result = subprocess.call(args)
            return result

        @lint
        def add_class():
            # type: () -> int
            result = subprocess.call(['tools/find-add-class'])
            return result

        @lint
        def css():
            # type: () -> int
            result = subprocess.call(['tools/check-css'])
            return result

        @lint
        def jslint():
            # type: () -> int
            result = subprocess.call(['tools/node', 'tools/jslint/check-all.js']
                                     + by_lang['js'])
            return result

        @lint
        def puppet():
            # type: () -> int
            if not by_lang['pp']:
                return 0
            result = subprocess.call(['puppet', 'parser', 'validate'] + by_lang['pp'])
            return result

        @lint
        def custom_py():
            # type: () -> int
            failed = check_custom_checks_py()
            return 1 if failed else 0

        @lint
        def custom_nonpy():
            # type: () -> int
            failed = check_custom_checks_nonpy()
            return 1 if failed else 0

        @lint
        def pyflakes():
            # type: () -> int
            failed = check_pyflakes(options, by_lang)
            return 1 if failed else 0

        failed = run_parallel(lint_functions)

    sys.exit(1 if failed else 0)

if __name__ == '__main__':
    run()