#!/usr/bin/env python3

# python deps: requests, pyyaml
# non-python deps: aria2, git

import os
import pathlib
import requests
import shutil
import subprocess
import yaml


class StackageSession(object):
    def __init__(self):
        self._base_path = pathlib.Path(os.environ['TUNASYNC_WORKING_DIR'])

    def download(self, dir_, url, sha1=None, force=False):
        dir_path = self._base_path / dir_
        file_path = dir_path / url.split('/')[-1]
        if force and file_path.is_file():
            file_path.unlink()
        if file_path.is_file():
            print('{} exists, skipping'.format(file_path), flush=True)
        else:
            args = [
                'aria2c', url, '--dir={}'.format(
                    dir_path), '--out={}.tmp'.format(url.split('/')[-1]),
                '--file-allocation=none', '--quiet=true'
            ]
            if sha1:
                args.append('--checksum=sha-1={}'.format(sha1))
            subprocess.run(args, check=True)
            shutil.move('{}.tmp'.format(file_path), file_path)
            print('Downloaded {} to {}'.format(url, file_path), flush=True)

    def load_stack_setup(self):
        d = yaml.load(
            requests
                .get('https://raw.githubusercontent.com/commercialhaskell/stackage-content/master/stack/stack-setup-2.yaml')
                .content
        )
        for platform in d['ghc']:
            for ver in d['ghc'][platform]:
                self.download(
                    'ghc',
                    d['ghc'][platform][ver]['url'],
                    d['ghc'][platform][ver]['sha1'],
                )
                d['ghc'][platform][ver]['url'] = (
                    'http://mirrors.tuna.tsinghua.edu.cn/stackage/ghc/{}'
                    .format(d['ghc'][platform][ver]['url'].split('/')[-1])
                )

        if 'msys2' in d:
            if 'windows32' in d['msys2']:
                print('windows32')
                d['msys2']['windows32']['url'] = d['msys2']['windows32']['url'].replace(
                    'https://github.com/fpco/stackage-content/releases/download/',
                    'https://mirrors.tuna.tsinghua.edu.cn/github-release/commercialhaskell/stackage-content/msys2-')
            if 'windows64' in d['msys2']:
                print('windows64')
                d['msys2']['windows64']['url'] = d['msys2']['windows64']['url'].replace(
                    'https://github.com/commercialhaskell/stackage-content/releases/download/',
                    'https://mirrors.tuna.tsinghua.edu.cn/github-release/commercialhaskell/stackage-content/')

        if 'sevenzexe-info' in d:
            d['sevenzexe-info']['url'] = 'https://mirrors.tuna.tsinghua.edu.cn/github-raw/fpco/minghc/master/bin/7z.exe'

        if 'sevenzdll-info' in d:
            d['sevenzdll-info']['url'] = 'https://mirrors.tuna.tsinghua.edu.cn/github-raw/fpco/minghc/master/bin/7z.dll'

        for i in ['portable-git', 'stack', 'ghcjs']:
            del d[i]
        with open(self._base_path / 'stack-setup.yaml', 'w') as f:
            yaml.dump(d, f, default_flow_style=False)
        print('Loaded stack-setup.yaml', flush=True)

    def load_stackage_snapshots(self):
        for channel in ['lts-haskell', 'stackage-nightly']:
            if (self._base_path / channel).is_dir():
                args = ['git', '-C', self._base_path / channel, 'pull']
            else:
                args = ['git', '-C', self._base_path, 'clone', '--depth', '1',
                        'https://github.com/commercialhaskell/{}.git'.format(channel)]
            subprocess.run(args, check=True)
            print('Loaded {}'.format(channel), flush=True)

        self.download(
            '',
            'https://www.stackage.org/download/snapshots.json',
            force=True,
        )
        print('Loaded snapshots.json', flush=True)


def stackage_snapshots_git_sync():
    base_path = pathlib.Path(os.environ['TUNASYNC_WORKING_DIR'])
    working_dir = base_path / "stackage-snapshots"
    if working_dir.is_dir():
        subprocess.run(
            ['git', '-C', working_dir.as_posix(), 'pull'], check=True)
    else:
        subprocess.run(['git', '-C', base_path.as_posix(), 'clone', '--depth', '1',
                        'https://github.com/commercialhaskell/stackage-snapshots.git'], check=True)


if __name__ == '__main__':
    s = StackageSession()
    stackage_snapshots_git_sync()
    s.load_stackage_snapshots()
    s.load_stack_setup()