#!/usr/bin/env python3

from subprocess import Popen, PIPE
import sys
import json
import os
import argparse
from pathlib import Path
import shutil
import tempfile
import requests


repos = ['https://github.com/lightningd/plugins']


def py_entry_guesses(name):
    return [name, f'{name}.py', '__init__.py']


def unsupported_entry(name):
    return [f'{name}.go', f'{name}.sh']


class InstInfo:
    def __init__(self, name, url, git_url):
        self.name = name
        self.repo = url         # Used for 'git clone'
        self.git_url = git_url  # API access for github repos
        self.entry = None
        self.deps = None
        self.subdir = None
        self.commit = None

    def __repr__(self):
        return f'<InstInfo object>\n'\
               f'name: {self.name}\nrepo: {self.repo}\ngit: {self.git_url}'\
               f'\nentry:{self.entry}\ndepency source:{self.deps}'

    def get_inst_details(self):
        """
        Populate installation details from a github repo url.
        Return True if all data is found.
        """
        r = requests.get(self.git_url)
        if r.status_code != 200:
            return False
        if 'git/tree' in self.git_url:
            tree = r.json()['tree']
        else:
            tree = r.json()
        entry_guesses = py_entry_guesses(self.name)
        for g in entry_guesses:
            for f in tree:
                if f['path'] == g:
                    self.entry = g
                    break
            if self.entry is not None:
                break
        if self.entry is None:
            for g in unsupported_entry(self.name):
                for f in tree:
                    if f['path'] == g:
                        # FIXME: This should be easier to implement
                        print(f'entrypoint {g} is not yet supported')
                        return False
        dependency_info = ['requirements.txt', 'pyproject.toml']
        for d in dependency_info:
            for f in tree:
                if f['path'] == d:
                    self.deps = d
                    break
            if self.deps is not None:
                break
        if not self.entry:
            return False
        if not self.deps:
            return False
        return True


def create_dir(r, directory):
    """Creation of a directory at path `d` with a maximum new dir depth `r`"""
    if os.path.exists(directory):
        return True
    elif r <= 0:
        return False
    elif create_dir(r-1, os.path.split(directory)[0]):
        os.mkdir(directory, 0o777)
        print(f'created directory {directory}')
        if os.path.exists(directory):
            return True


def remove_dir(target):
    try:
        shutil.rmtree(target)
        return True
    except NotADirectoryError:
        print(f"Tried to remove directory {target} that does not exist.")
    except PermissionError:
        print(f"Permission denied removing dir: {target}")
    return False


class Config():
    """A generic class for procuring, reading and editing config files"""
    def obtain_config(self, config_path, default_text):
        """Return a config file from the desired location. Create one with
        default_text if it cannot be found."""
        if isinstance(config_path, type(None)):
            raise Exception("Generic config must be passed a config_path.")
        assert isinstance(config_path, str)
        # FIXME: warn if reckless dir exists, but conf not found
        if os.path.exists(config_path):
            with open(config_path, 'r+') as f:
                config_content = f.readlines()
            return config_content
        print(f'config file not found: {config_path}')
        confirm = input('press [Y] to create one now.\n')
        if confirm.upper() != 'Y':
            sys.exit(1)
        parent_path = os.path.split(config_path)[0]
        # Create up to one parent in the directory tree.
        if create_dir(1, parent_path):
            with open(self.conf_fp, 'w') as f:
                f.write(default_text)
                # FIXME: Handle write failure
                return default_text
        else:
            print('could not create the parent directory')
            return None

    def editConfigFile(self, addline, removeline):
        remove_these_lines = []
        with open(self.conf_fp, 'r') as reckless_conf:
            original = reckless_conf.readlines()
            empty_lines = []
            for n, l in enumerate(original):
                if l.strip() == removeline:
                    remove_these_lines.append(n)
                    continue
                if l.strip() == '':
                    empty_lines.append(n)
                    if n-1 in empty_lines:
                        # The white space is getting excessive.
                        remove_these_lines.append(n)
                        continue
            with open(self.conf_fp, 'w') as conf_write:
                # no need to write if passed 'None'
                line_exists = not bool(addline)
                for n, l in enumerate(original):
                    if n not in remove_these_lines:
                        if n > 0:
                            conf_write.write(f'\n{l.strip()}')
                        else:
                            conf_write.write(l.strip())
                        if addline == l:
                            # addline is idempotent
                            line_exists = True
                if not line_exists:
                    conf_write.write(f'\n{addline}')

    def __init__(self, path=None, default_text=None):
        assert path is not None
        assert default_text is not None
        self.conf_fp = path
        self.content = self.obtain_config(self.conf_fp, default_text)


class RecklessConfig(Config):
    """Reckless config (by default, specific to the bitcoin network only.)
    This is inherited by the lightningd config and contains all reckless
    maintained plugins."""

    def enable_plugin(self, plugin_path):
        """Handle persistent plugin loading via config"""
        self.editConfigFile(f'plugin={plugin_path}',
                            f'disable-plugin={plugin_path}')

    def disable_plugin(self, plugin_path):
        """Handle persistent plugin disabling via config"""
        self.editConfigFile(f'disable-plugin={plugin_path}',
                            f'plugin={plugin_path}')

    def __init__(self, path=None, default_text=None):
        if path is None:
            path = os.path.join(LIGHTNING_DIR, 'reckless',
                                'bitcoin-reckless.conf')
        if default_text is None:
            default_text = '# This configuration file is managed by reckles' +\
                           's to activate and disable\n# reckless-installed' +\
                           ' plugins\n\n'
        Config.__init__(self, path=str(path), default_text=default_text)
        self.reckless_dir = os.path.split(path)[0]


class LightningBitcoinConfig(Config):
    """lightningd config specific to the bitcoin network. This is inherited by
    the main lightningd config and in turn, inherits bitcoin-reckless.conf."""

    def __init__(self, path=None, default_text=None):
        if path is None:
            path = os.path.join(LIGHTNING_DIR, 'bitcoin', 'config')
        if default_text is None:
            default_text = "# This config was autopopulated by reckless\n\n"
        Config.__init__(self, path=str(path),
                        default_text=default_text)


class InferInstall():
    """Once a plugin is installed, we may need its directory and entrypoint"""
    def __init__(self, name):
        reck_contents = os.listdir(RECKLESS_CONFIG.reckless_dir)
        if name[-3:] == '.py':
            name = name[:-3]
        if name in reck_contents:
            self.dir = os.path.join(RECKLESS_CONFIG.reckless_dir, name)
        else:
            raise Exception(f"Could not find a reckless directory for {name}")
        plug_contents = os.listdir(os.path.join(RECKLESS_CONFIG.reckless_dir,
                                                name))
        for n in py_entry_guesses(name):
            if n in plug_contents:
                self.entry = os.path.join(self.dir, n)
                self.name = n
                return
        raise Exception(f'plugin entrypoint not found in {self.dir}')


def help(target):
    if len(target) > 0:
        print(globals()[target[0]].__doc__)
    else:
        parser.print_help(sys.stdout)


def verbose(*args):
    if not IS_VERBOSE:
        return
    print(*args)


def _search_repo(name, url):
    """look in given repo and, if found, populate InstInfo"""
    # Remove api subdomain, subdirectories, etc.
    repo = url.split('/')
    while '' in repo:
        repo.remove('')
    repo_name = None
    for i in range(len(repo)):
        if 'github.com' in repo[i]:
            # Extract user and repo name
            start = i + 1
            if repo[start] == 'repo':
                # Maybe we were passed an api.github.com/repo/<user> url
                start = start + 1
            repo_user = repo[start]
            repo_name = repo[start+1]
            break
    # FIXME: Handle non-github repos.
    # Get details from the github API.
    if repo_name is not None:
        api_url = f'https://api.github.com/repos/{repo_user}/' + \
                  f'{repo_name}/contents/'
    plugins_cont = api_url
    r = requests.get(plugins_cont, timeout=5)
    if r.status_code != 200:
        print("Plugin repository unavailable")
        return False
    # Repo is for this plugin
    if repo_name == name:
        MyPlugin = InstInfo(name, f'https://github.com/{repo_user}/'
                            f'{repo_name}', api_url)
        if not MyPlugin.get_inst_details():
            return False
        return MyPlugin
    # Repo contains multiple plugins?
    for x in r.json():
        if x["name"] == name:
            # Look for the rest of the install details
            # These are in lightningd/plugins directly
            if 'lightningd/plugins/' in x['html_url']:
                MyPlugin = InstInfo(name,
                                    'https://github.com/lightningd/plugins',
                                    x['git_url'])
                MyPlugin.subdir = x['name']
            # submodules from another github repo
            else:
                MyPlugin = InstInfo(name, x['html_url'], x['git_url'])
                # Submodule URLs are appended with /tree/<commit hash>
                if MyPlugin.repo.split('/')[-2] == 'tree':
                    MyPlugin.commit = MyPlugin.repo.split('/')[-1]
                    MyPlugin.repo = MyPlugin.repo.split('/tree/')[0]
                    verbose(f'repo using commit: {MyPlugin.commit}')
            if not MyPlugin.get_inst_details():
                return False
            return MyPlugin
    return False


def _install_plugin(src):
    """make sure the repo exists and clone it."""
    verbose(f'Install requested from {src}.')
    if RECKLESS_CONFIG is None:
        print('error: reckless install directory unavailable')
        sys.exit(2)
    req = requests.get(src.repo, timeout=20)
    if not req.status_code == 200:
        print('plugin source repository unavailable')
        sys.exit(1)
    # Use a unique directory for each cloned repo.
    clone_path = 'reckless-{}'.format(str(hash(os.times()))[-9:])
    clone_path = os.path.join(tempfile.gettempdir(), clone_path)
    inst_path = os.path.join(RECKLESS_CONFIG.reckless_dir,
                             src.name)
    if os.path.exists(clone_path):
        verbose(f'{clone_path} already exists - deleting')
        shutil.rmtree(clone_path)
    # clone git repository to /tmp/reckless-...
    if ('http' in src.repo[:4]) or ('github.com' in src.repo):
        # Ugly, but interactively handling stderr gets hairy.
        if IS_VERBOSE:
            git = Popen(['git', 'clone',  src.repo, clone_path],
                        stdout=PIPE)
        else:
            git = Popen(['git', 'clone',  src.repo, clone_path],
                        stdout=PIPE, stderr=PIPE)
        git.wait()
        if git.returncode != 0:
            if git.stderr:
                print(git.stderr.read().decode())
            if os.path.exists(clone_path):
                remove_dir(clone_path)
            print('Error: Failed to clone repo')
            return False
    plugin_path = clone_path
    if src.subdir is not None:
        plugin_path = os.path.join(clone_path, src.subdir)
    os.chdir(plugin_path)
    if src.commit:
        verbose(f"Checking out commit {src.commit}")
        checkout = Popen(['git', 'checkout', src.commit],
                         stdout=PIPE, stderr=PIPE)
        checkout.wait()
        if checkout.returncode != 0:
            print(f'failed to checkout referenced commit {src.commit}')
            return False
    # Install dependencies via requirements.txt
    install_methods = {
        'requirements.txt': ['pip', 'install', '-r', 'requirements.txt'],
        'pyproject.toml': ['pip', 'install', '-e', '.']
    }

    if src.deps is not None:
        verbose(f'installing dependencies using {src.deps}')
        procedure = install_methods[src.deps]
        pip = Popen(procedure, stdout=PIPE)
        pip.wait()
        if pip.returncode == 0:
            print('dependencies installed successfully')
        else:
            print('error encountered installing dependencies')
            verbose(pip.stdout.read())
            return False
    test = Popen([os.path.join(plugin_path, src.entry)],
                 stdout=PIPE, stderr=PIPE, universal_newlines=True)
    test_log = []
    with test.stderr:
        for line in test.stderr:
            test_log.append(line.strip('\n'))
    test.wait()
    # FIXME: add noexec test/warning. Maybe try chmod entrypoint.
    if test.returncode != 0:
        verbose("plugin testing error:")
        for line in test_log:
            verbose(f'  {line}')
        print('plugin testing failed')
        return False

    # Find this cute little plugin a forever home
    shutil.copytree(plugin_path, inst_path)
    print(f'plugin installed: {inst_path}')
    remove_dir(clone_path)
    return True


def install(plugin_name):
    """reckless install <plugin>
    downloads plugin from source repos, installs and activates plugin"""
    assert isinstance(plugin_name, list)
    plugin_name = plugin_name[0]
    if plugin_name is None:
        print('missing argument: plugin_name')

    src = search([plugin_name])

    if src:
        verbose(f'Retrieving {plugin_name} from {src.repo}')
        if not _install_plugin(src):
            print('installation aborted')
            sys.exit(1)
        inst_path = os.path.join(RECKLESS_CONFIG.reckless_dir,
                                 src.name,
                                 src.entry)
        RECKLESS_CONFIG.enable_plugin(inst_path)
        enable([plugin_name])


def uninstall(plugin_name):
    """reckless uninstall <plugin>
    disables plugin and deletes the plugin's reckless dir"""
    assert isinstance(plugin_name, list)
    plugin_name = plugin_name[0]
    if plugin_name is not None:
        # FIXME: Do something here.
        print('Uninstalling plugin {}'.format(plugin_name))
        disable([plugin_name])
        plugin_dir = os.path.join(RECKLESS_CONFIG.reckless_dir, plugin_name)
        verbose("looking for {}".format(plugin_dir))
        if remove_dir(plugin_dir):
            print(f"{plugin_name} uninstalled successfully.")


def search(plugin_name):
    """reckless search <plugin>
    searches plugin index for plugin"""
    plugin_name = plugin_name[0]
    if plugin_name is None:
        print('plugin name required')
        return None
    ordered_repos = RECKLESS_SOURCES
    for r in RECKLESS_SOURCES:
        if r.split('/')[-1].lower() == plugin_name.lower():
            ordered_repos.remove(r)
            ordered_repos.insert(0, r)
    for r in ordered_repos:
        p = _search_repo(plugin_name, r)
        if p:
            print(f"found {p.name} in repo: {p.repo}")
            verbose(f"entry: {p.entry}")
            if p.subdir:
                verbose(f'sub-directory: {p.subdir}')
            return p
    print(f'Unable to locate source for plugin {plugin_name}')


def lightning_cli_available():
    clncli = Popen(['lightning-cli'], stdout=PIPE, stderr=PIPE)
    clncli.wait(timeout=1)
    if clncli.returncode == 0:
        return True
    else:
        return False


def enable(plugin_name):
    """reckless enable <plugin>
    dynamically activates plugin and adds to config (persistent)"""
    assert isinstance(plugin_name, list)
    plugin_name = plugin_name[0]
    if plugin_name is None:
        sys.stderr.write('Plugin name required.')
        sys.exit(1)
    inst = InferInstall(plugin_name)
    path = inst.entry
    if not os.path.exists(path):
        print('cannot find installed plugin at expected path {}'
              .format(path))
        sys.exit(1)
    verbose('activating {}'.format(plugin_name))

    if not lightning_cli_available():
        # Config update should not be dependent upon lightningd running
        RECKLESS_CONFIG.enable_plugin(path)
        return

    clncli = Popen(['lightning-cli', 'plugin', 'start', path], stdout=PIPE)
    clncli.wait(timeout=3)
    if clncli.returncode == 0:
        RECKLESS_CONFIG.enable_plugin(path)
        print('{} enabled'.format(plugin_name))
    else:
        err = eval(clncli.stdout.read().decode().replace('\n', ''))['message']
        if ': already registered' in err:
            RECKLESS_CONFIG.enable_plugin(path)
            verbose(f'{inst.name} already registered with lightningd')
            print('{} enabled'.format(plugin_name))
        else:
            print(f'reckless: {inst.name} failed to start!')
            print(err)
    sys.exit(clncli.returncode)


def disable(plugin_name):
    """reckless disable <plugin>
    deactivates an installed plugin"""
    assert isinstance(plugin_name, list)
    plugin_name = plugin_name[0]
    if plugin_name is None:
        sys.stderr.write('Plugin name required.')
        sys.exit(1)
    inst = InferInstall(plugin_name)
    path = inst.entry
    if not os.path.exists(path):
        sys.stderr.write(f'Could not find plugin at {path}\n')
        sys.exit(1)
    if not lightning_cli_available():
        RECKLESS_CONFIG.disable_plugin(path)
        print(f'{plugin_name} disabled')
        return
    clncli = Popen(['lightning-cli', 'plugin', 'stop', path],
                   stdout=PIPE, stderr=PIPE)
    clncli.wait(timeout=3)
    output = json.loads(clncli.stdout.read().decode()
                        .replace('\n', '').replace('   ', ''))
    # print(output)
    if ('code' in output.keys() and output['code'] == -32602):
        print('plugin not currently running')
    elif clncli.returncode != 0:
        print('lightning-cli plugin stop failed')
        sys.stderr.write(clncli.stderr.read().decode())
        sys.exit(clncli.returncode)
    RECKLESS_CONFIG.disable_plugin(path)
    print(f'{plugin_name} disabled')


def load_config(reckless_dir=None, network='bitcoin'):
    """Initial directory discovery and config file creation."""
    if reckless_dir is None:
        reckless_dir = str(os.path.join(LIGHTNING_DIR, 'reckless'))
    else:
        if not os.path.isabs(reckless_dir):
            reckless_dir = os.path.join(os.getcwd(), reckless_dir)
    # Reckless applies to the bitcoin network configuration by default.
    if network == 'bitcoin':
        reck_conf_path = os.path.join(reckless_dir, 'bitcoin-reckless.conf')
        # This config file inherits the RecklessConfig.
        net_conf = LightningBitcoinConfig()
    elif network == 'regtest':
        reck_conf_path = os.path.join(reckless_dir, 'regtest-reckless.conf')
        regtest_path = os.path.join(LIGHTNING_DIR, 'regtest', 'config')
        # Actually the regtest network config
        net_conf = LightningBitcoinConfig(path=regtest_path)
    # Reckless manages plugins here.
    reckless_conf = RecklessConfig(path=reck_conf_path)
    if not reckless_conf:
        print('Error: reckless config file could not be written')
        sys.exit(1)
    if not net_conf:
        print('Error: could not load or create the network specific lightningd'
              ' config (default .lightning/bitcoin)')
        sys.exit(1)
    net_conf.editConfigFile(f'include {reckless_conf.conf_fp}', None)
    return reckless_conf


def get_sources_file():
    return os.path.join(RECKLESS_DIR, '.sources')


def sources_from_file():
    sources_file = get_sources_file()
    read_sources = []
    with open(sources_file, 'r') as f:
        for src in f.readlines():
            if len(src.strip()) > 0:
                read_sources.append(src.strip())
        # print('loaded sources:', repos)
        return read_sources


def loadSources():
    """Look for the repo sources file"""
    sources_file = get_sources_file()
    # This would have been created if possible
    if not os.path.exists(sources_file):
        print('Warning: Reckless requires write access')
        Config(path=sources_file,
               default_text='https://github.com/lightningd/plugins')
        return ['https://github.com/lightningd/plugins']
    return sources_from_file()


def add_source(src):
    """Additional git repositories, directories, etc. are passed here
    singly."""
    # Is it a file?
    assert isinstance(src, str)
    maybe_path = os.path.realpath(src)
    if os.path.exists(maybe_path):
        # FIXME: This should handle either a directory or a git repo
        if os.path.isdir(maybe_path):
            print(f'Plugin source directory found: {maybe_path}')
    elif 'github.com' in src:
        my_file = Config(path=str(get_sources_file()),
                         default_text='https://github.com/lightningd/plugins')
        my_file.editConfigFile(src, None)


def remove_source(src):
    assert isinstance(src, str)
    if src in sources_from_file():
        my_file = Config(path=get_sources_file(),
                         default_text='https://github.com/lightningd/plugins')
        my_file.editConfigFile(None, src)
        print('plugin source removed')
    else:
        print(f'source not found: {src}')


def list_source():
    for src in sources_from_file():
        print(src)


def source(cmd):
    """reckless source <add/remove/list>
    reckless source add <github repository url>      adds a source to search
    reckless source remove <github repository url>   removes a source
    reckless source list                             lists all sources
    """
    assert isinstance(cmd, list)
    if cmd[0] == 'add':
        for src in cmd[1:]:
            add_source(src)
    elif cmd[0] == 'remove' or cmd[0] == 'rem' or cmd[0] == 'rm':
        for src in cmd[1:]:
            remove_source(src)
    elif cmd[0] == 'list':
        list_source()
    else:
        print('unrecognized argument to reckless source: {cmd[0]}')
        sys.exit(1)


def sources(cmd):
    # alias to improve ux
    source(cmd)


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument(dest='command', help='install/uninstall/search/enable'
                        '/disable/source/help',
                        type=str)
    # Here we pass a list of argument in as target. This is useful for
    # subcommands (i.e., reckless source add <repo>) as well as for passing
    # lists of plugins to handle in sequence (to be implemented.)
    parser.add_argument(dest='target', nargs='*', default=None, help='target',
                        type=str)
    # This default depends on the .lightning directory
    parser.add_argument('-d', '--reckless-dir',
                        help='specify a data directory for reckless to use',
                        type=str, default=None)
    parser.add_argument('-l', '--lightning',
                        help='lightning data directory (default:~/.lightning)',
                        type=str,
                        default=Path.home().joinpath('.lightning'))
    parser.add_argument('-r', '--regtest', action='store_true')
    parser.add_argument('-v', '--verbose', action='store_true')
    args = parser.parse_args()

    if hasattr(args, 'command'):
        if args.command in ['install', 'uninstall', 'search', 'enable',
                            'disable', 'help', 'source', 'sources']:
            NETWORK = 'regtest' if args.regtest else 'bitcoin'
            LIGHTNING_DIR = Path(args.lightning)
            if args.reckless_dir:
                RECKLESS_DIR = args.reckless_dir
            else:
                RECKLESS_DIR = os.path.join(LIGHTNING_DIR, 'reckless')
            RECKLESS_CONFIG = load_config(reckless_dir=RECKLESS_DIR,
                                          network=NETWORK)
            RECKLESS_SOURCES = loadSources()
            IS_VERBOSE = bool(args.verbose)
            globals()[args.command](args.target)
            sys.exit(0)
        else:
            print(f'{args.command}: command unrecognized')