#!/usr/bin/env python -u
from __future__ import print_function
import os
from argparse import ArgumentParser, FileType
from datetime import datetime
from shutil import rmtree
from subprocess import check_call, check_output, CalledProcessError
from tempfile import mkdtemp
import yaml
rel = lambda *x: os.path.abspath(os.path.join(os.path.dirname(__file__), *x))
def run_ignore_codes(fn, args, codes):
    try:
        return fn(args)
    except CalledProcessError as e:
        if e.returncode not in codes:
            raise
        return e.output
def run(args, silent=False, get_output=False, ignore_codes=None):
    if get_output:
        fn = check_output
    else:
        fn = check_call
    try:
        if not silent:
            print('$ ' + ' '.join(args))
        if ignore_codes:
            result = run_ignore_codes(fn, args, ignore_codes)
        else:
            result = fn(args)
        if get_output:
            return result
        else:
            return True
    except Exception as e:
        print('# C&O error: {}'.format(e))
        print('# C&O job failed')
        return False
def now():
    return datetime.utcnow().strftime('%Y-%m-%dT%H:%M:%S+00:00')
def read_linter_config(name, path=rel('linters')):
    try:
        fd = open(os.path.join(path, '{}.yml'.format(name)))
    except Exception as e:
        print("# C&O couldn't load linter config: {}".format(e))
        return None
    with fd:
        try:
            return yaml.safe_load(fd)
        except Exception as e:
            print("# C&O couldn't parse linter config: {}".format(e))
            return None
def prevalidate(config):
    ok = True
    if 'url' not in config:
        print("# C&O config doesn't have 'url' defined.")
        ok = False
    if 'scm' not in config:
        print("# C&O config doesn't have 'scm' defined.")
        ok = False
    elif config['scm'] != 'hg':
        print("# C&O checker doesn't support {} yet.".format(config['scm']))
        ok = False
    return ok
def execute(tmp, config):
    if not prevalidate(config):
        return False
    os.chdir(tmp)
    source = './source'
    print('# C&O task: clone')
    print('# C&O project URL: {}'.format(config['url']))
    os.environ['HGPLAIN'] = '1'
    if not run(['hg', 'clone', config['url'], source]):
        return False
    print('$ cd {}'.format(source))
    os.chdir(source)
    if not run(['hg', 'sum']):
        return False
    template = (r'# C&O commit: {rev}:{node}\n'
                r'# C&O commit branch: {branch}\n'
                r'# C&O commit date: {date|isodatesec}\n'
                r'# C&O commit author: {author|person}\n'
                r'# C&O commit message: {desc|firstline}\n')
    if not run(['hg', 'log', '-r', '.', '-T', template], silent=True):
        return False
    print('# C&O task: setup')
    to_install = [l['name'] for l in config.get('linters', []) if 'name' in l]
    print('# C&O linters to install: {}'.format(' '.join(to_install)))
    linter_config = {}
    for linter in config.get('linters', []):
        if 'name' not in linter:
            continue
        name = linter['name']
        if name in linter_config:
            continue
        lc = read_linter_config(name)
        if lc is None or 'exec' not in lc:
            continue
        linter_config[name] = lc
        for item in lc.get('setup', []):
            if not run(item):
                return False
        if 'version' in lc and not run(lc['exec'] + lc['version']):
            return False
    print('# C&O linters installed: {}'.format(' '.join(linter_config.keys())))
    print('# C&O task: checks')
    for linter in config.get('linters', []):
        if 'name' not in linter or 'include' not in linter:
            continue
        if linter['name'] not in linter_config:
            continue
        cmd = ['hg', 'files']
        for pat in linter['include']:
            cmd.extend(('-I', pat))
        for pat in linter.get('exclude', []):
            cmd.extend(('-X', pat))
        files = run(cmd, silent=True, get_output=True, ignore_codes=(1,))
        if files is False:
            return False
        lc = linter_config[linter['name']]
        for f in files.splitlines():
            cmd = lc['exec']
            flags = lc.get('flags', []) + linter.get('flags', [])
            pf = lc.get('post_flags', []) + linter.get('post_flags', [])
            codes = lc.get('codes', (1,))
            if not run(cmd + flags + [f] + pf, ignore_codes=codes):
                return False
    return True
def wrapper(config):
    print('# C&O job started: {}'.format(now()))
    tmp = mkdtemp(prefix='candolint.')
    if not execute(tmp, config):
        print('# C&O job failed')
    print('# C&O task: cleanup')
    rmtree(tmp)
    print('# C&O job finished: {}'.format(now()))
def bad_exit():
    print('# C&O job failed (exception not caught)')
    print('# C&O job finished: {}'.format(now()))
def main():
    parser = ArgumentParser()
    helptext = 'project configuration file (YAML)'
    parser.add_argument('config', type=FileType('r'), help=helptext)
    args = parser.parse_args()
    config = yaml.safe_load(args.config)
    try:
        wrapper(config)
    except:
        bad_exit()
if __name__ == '__main__':
    main()