import argparse
import re
import shutil
import subprocess
import sys
import textwrap
import time

from voussoirkit import passwordy
from voussoirkit import winwhich

GIT = winwhich.which('git')
PY = winwhich.which('py')
TWINE = winwhich.which('twine')

BUMP_PATTERN = r'Bump to version (\d+\.\d+\.\d+)\.'

DEBUG = False

class PypiReleaseError(Exception):
    pass

class BadSetup(PypiReleaseError):
    pass

class DirtyState(PypiReleaseError):
    pass

class NotSemver(PypiReleaseError):
    pass

class VersionOutOfOrder(PypiReleaseError):
    pass

# HELPER FUNCTIONS
################################################################################
def bump_version(version, versionbump):
    (major, minor, patch) = [int(x) for x in version.split('.')]
    if versionbump == 'major':
        major += 1
        minor = 0
        patch = 0
    elif versionbump == 'minor':
        minor += 1
        patch = 0
    elif versionbump == 'patch':
        patch += 1
    else:
        raise ValueError(f'versionbump should be major, minor, or patch, not {versionbump}.')
    version = f'{major}.{minor}.{patch}'
    return version

def check_call(command, show_command=True):
    if DEBUG or show_command:
        print_command(command)
    return subprocess.check_call(command)

def check_output(command, show_command=True):
    if DEBUG or show_command:
        print_command(command)
    return subprocess.check_output(command, stderr=subprocess.STDOUT)

def pick_versionbump(major, minor, patch):
    mmp = (major, minor, patch)
    if not all(b in [True, False, None] for b in mmp):
        raise TypeError('major, minor, patch should all be True, False, or None.')

    if mmp in [(False, False, False), (None, None, None)]:
        versionbump = 'patch'

    elif mmp.count(True) > 1:
        raise TypeError('Must only pick one of major, minor, patch.')

    elif major:
        versionbump = 'major'

    elif minor:
        versionbump = 'minor'

    elif patch:
        versionbump = 'patch'

    else:
        raise TypeError()

    return versionbump

def print_command(command):
    cmd = [('"%s"' % x) if (' ' in x or x == '') else x for x in command]
    cmd = ' '.join(cmd)
    cmd = cmd.strip()
    cmd = cmd.replace(GIT, 'git')
    cmd = cmd.replace(PY, 'py')
    cmd = cmd.replace(TWINE, 'twine')
    print(f'> {cmd}')

def semver_split(semver):
    original = semver
    try:
        semver = semver.strip('v')
        mmp = semver.split('.')
        mmp = tuple(int(x) for x in mmp)
        (major, minor, patch) = mmp
        return mmp
    except Exception:
        raise NotSemver(original)

def slowprint(s=None):
    slow = 0.05
    if s is None:
        print()
        time.sleep(slow)
        return
    for line in s.split('\n'):
        print(line)
        time.sleep(slow)

# SETUP.PY
################################################################################
def extract_info_from_setup():
    handle = open('setup.py', 'r', encoding='utf-8')
    with handle:
        setup_py = handle.read()

    name = re.findall(r'''\bname=["']([A-Za-z0-9_-]+)["']''', setup_py)
    if len(name) != 1:
        raise BadSetup(f'Expected to find 1 name but found {len(name)}.')
    name = name[0]

    version = re.findall(r'''\bversion=["'](\d+\.\d+\.\d+)["']''', setup_py)
    if len(version) != 1:
        raise BadSetup(f'Expected to find 1 version but found {len(version)}.')
    version = version[0]

    return (setup_py, name, version)

def update_info_in_setup(setup_py, name, version):
    re_from = fr'''\bname=(["'])({name})(["'])'''
    re_to = fr'''name=\1\2\3'''
    setup_py = re.sub(re_from, re_to, setup_py)

    re_from = fr'''\bversion=(["'])(\d+\.\d+\.\d+)(["'])'''
    re_to = fr'''version=\g<1>{version}\g<3>'''
    setup_py = re.sub(re_from, re_to, setup_py)
    return setup_py

def write_setup(setup_py):
    handle = open('setup.py', 'w', encoding='utf-8')
    with handle:
        handle.write(setup_py)

# GIT
################################################################################
def git_assert_current_greater_than_latest(latest_release_version, new_version):
    if latest_release_version >= semver_split(new_version):
        raise VersionOutOfOrder(f'New version should be {new_version} but {latest_release_version} already exists.')

def git_assert_no_stashes():
    command = [GIT, 'stash', 'list']
    output = check_output(command, show_command=False)
    lines = output.strip().splitlines()
    if len(lines) != 0:
        raise DirtyState('Please ensure there are no stashes.')

def git_assert_pushable():
    command = [GIT, 'fetch', '--all']
    check_output(command, show_command=False)

    command = [GIT, 'merge-base', '@', '@{u}']
    merge_base = check_output(command, show_command=False).strip()

    command = [GIT, 'rev-parse', '@']
    my_head = check_output(command, show_command=False).strip()

    command = [GIT, 'rev-parse', '@{u}']
    remote_head = check_output(command, show_command=False).strip()

    if my_head == remote_head:
        pass
    elif my_head == merge_base:
        git_commits_since(merge_base.decode(), show=True, inclusive=True)
        raise DirtyState('Cant push, need to pull first.')
    elif remote_head == merge_base:
        pass
    else:
        git_commits_since(merge_base.decode(), show=True, inclusive=True)
        raise DirtyState('Cant push, diverged from remote.')

def git_commit_bump(version):
    command = [GIT, 'add', 'setup.py']
    check_output(command)

    command = [GIT, 'commit', '-m', f'Bump to version {version}.']
    check_output(command)

def git_commits_since(commit, show, inclusive=False):
    if commit:
        if inclusive:
            commit += '~1'
        command = [GIT, '--no-pager', 'log', '--oneline', '--graph', '--branches', '--remotes', f'{commit}..']
    else:
        command = [GIT, '--no-pager', 'log', '--oneline', '--graph']

    if show:
        check_call(command, show_command=False)
    else:
        output = check_output(command, show_command=False)
        lines = output.strip().splitlines()
        return lines

def git_current_remote_branch():
    command = [GIT, 'rev-parse', '--abbrev-ref', '--symbolic-full-name', '@{u}']
    output = check_output(command, show_command=False)
    output = output.strip().decode()
    (remote, branch) = output.split('/')
    return (remote, branch)

def git_determine_latest_release():
    (latest_tagged_commit, latest_tag_version) = git_latest_tagged_commit()
    (latest_bump_commit, latest_bump_version) = git_latest_bump_commit()

    if latest_tagged_commit is None:
        latest_release_commit = latest_bump_commit
        latest_release_version = latest_bump_version

    elif latest_bump_commit is None:
        latest_release_commit = latest_tagged_commit
        latest_release_version = latest_tag_version

    elif latest_tag_version > latest_bump_version:
        latest_release_commit = latest_tagged_commit
        latest_release_version = latest_tag_version

    else:
        latest_release_commit = latest_bump_commit
        latest_release_version = latest_bump_version

    return (latest_release_commit, latest_release_version)

def git_latest_bump_commit():
    command = [GIT, 'log', '--oneline', '--no-abbrev-commit', '--grep', 'Bump to version *.', '-1']
    output = check_output(command, show_command=False)
    output = output.strip()
    if not output:
        return (None, None)
    commit = output.splitlines()[0].decode()
    version = re.search(BUMP_PATTERN, commit).group(1)
    version = semver_split(version)
    commit = commit.split()[0]
    return (commit, version)

def git_latest_tagged_commit():
    command = [GIT, 'log', '--oneline', '--no-abbrev-commit', '--tags=v*.*.*', '-1']
    output = check_output(command, show_command=False)
    output = output.strip()
    if not output:
        return (None, None)

    commit = output.splitlines()[0].decode().split()[0]

    for tag in git_tags_on_commit(commit):
        try:
            version = semver_split(tag)
            break
        except NotSemver:
            pass
    else:
        return (None, None)

    return (commit, version)

def git_push(remote, branch):
    command = [GIT, 'push', remote, branch]
    check_output(command)

def git_push_tag(remote, tag):
    command = [GIT, 'push', remote, tag]
    check_output(command)

def git_show_commit(commit):
    command = [GIT, 'show', '--oneline', '-s', commit]
    check_call(command, show_command=False)

def git_stash_push():
    token = passwordy.urandom_hex(32)
    command = [GIT, 'stash', 'push', '--include-untracked', '--message', token]
    output = check_output(command)

    command = [GIT, 'stash', 'list', '--grep', token]
    output = check_output(command).strip()

    did_stash = bool(output)
    return did_stash

def git_stash_restore():
    command = [GIT, 'stash', 'pop']
    output = check_output(command)

def git_tag_version(tag):
    command = [GIT, 'tag', '-a', tag, '-m', '']
    check_output(command)

def git_tags_on_commit(commit):
    command = [GIT, 'tag', '--points-at', commit]
    output = check_output(command, show_command=False)
    output = output.strip()
    if not output:
        return []
    output = output.decode().splitlines()
    return output

# PYPI
################################################################################
def pypi_upload(name):
    egg_dir = f'{name}.egg-info'

    command = [PY, 'setup.py', 'sdist']
    check_output(command)

    command = [TWINE, 'upload', '-r', 'pypi', 'dist\\*']
    check_output(command)

    shutil.rmtree('dist')
    shutil.rmtree(egg_dir)

def pypi_release(do_tag=False, versionbump='patch'):
    git_assert_no_stashes()
    git_assert_pushable()

    (setup_py, name, old_version) = extract_info_from_setup()
    new_version = bump_version(old_version, versionbump)
    new_tag = f'v{new_version}'

    (latest_release_commit, latest_release_version) = git_determine_latest_release()

    git_assert_current_greater_than_latest(latest_release_version, new_version)

    commits_since_last_release = git_commits_since(latest_release_commit, show=False)
    if len(commits_since_last_release) == 0:
        print('No new commits to release')
        return

    (remote, branch) = git_current_remote_branch()

    def linebreak():
        cli_width = shutil.get_terminal_size()[0]
        line = '#' * (cli_width - 1)
        line += '\r'
        line += f'# {name} {new_version} '
        line = f'\n{line}\n'
        slowprint(line)

    linebreak()

    slowprint(f'Upgrading {name} from {old_version} --> {new_version}.')
    slowprint()

    if latest_release_commit:
        slowprint('Latest release:')
        git_show_commit(latest_release_commit)
        slowprint()

    slowprint('This release:')
    git_commits_since(latest_release_commit, show=True)
    slowprint()

    setup_py = update_info_in_setup(setup_py, name, new_version)
    slowprint('Rewrite setup.py:')
    slowprint(textwrap.indent(setup_py, '>>> '))
    slowprint()

    slowprint(f'Release will be pushed to {remote} {branch}.')

    linebreak()

    input(f'PRESS ENTER TO RELEASE {name} {new_version}.')

    write_setup(setup_py)

    git_commit_bump(new_version)
    if do_tag:
        git_tag_version(new_tag)

    git_push(remote, branch)
    if do_tag:
        git_push_tag(remote, new_tag)

    did_stash = git_stash_push()
    pypi_upload(name)
    if did_stash:
        git_stash_restore()

    git_commits_since(latest_release_commit, show=True)

def pypi_release_argparse(args):
    global DEBUG
    if args.debug:
        DEBUG = True
    versionbump = pick_versionbump(args.major, args.minor, args.patch)
    try:
        return pypi_release(do_tag=args.do_tag, versionbump=versionbump)
    except subprocess.CalledProcessError as exc:
        print(exc.output)
        return 1

def main(argv):
    parser = argparse.ArgumentParser(description=__doc__)

    parser.add_argument('--major', dest='major', action='store_true')
    parser.add_argument('--minor', dest='minor', action='store_true')
    parser.add_argument('--patch', dest='patch', action='store_true')
    parser.add_argument('--do_tag', dest='do_tag', action='store_true')
    parser.add_argument('--debug', dest='debug', action='store_true')
    parser.set_defaults(func=pypi_release_argparse)

    args = parser.parse_args(argv)
    return args.func(args)

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