# -*- coding: utf-8  -*-
#
# Copyright (C) 2011-2014 Ben Kurtovic <ben.kurtovic@gmail.com>
# See the LICENSE file for details.

from __future__ import print_function

import os

from colorama import Fore, Style
from git import Repo, exc

__all__ = ["update_bookmarks", "update_directories"]

BOLD = Style.BRIGHT
RED = Fore.RED + BOLD
GREEN = Fore.GREEN + BOLD
BLUE = Fore.BLUE + BOLD
RESET = Style.RESET_ALL

INDENT1 = " " * 3
INDENT2 = " " * 7
ERROR = RED + "Error:" + RESET

def _read_config(repo, attr):
    """Read an attribute from git config."""
    try:
        return repo.git.config("--get", attr)
    except exc.GitCommandError:
        return None

def _update_repository(repo, current_only=False, rebase=False, merge=False,
                       verbose=False):
    """Update a single git repository by fetching remotes and rebasing/merging.

    The specific actions depend on the arguments given. We will fetch all
    remotes if *current_only* is ``False``, or only the remote tracked by the
    current branch if ``True``. By default, we will merge unless
    ``pull.rebase`` or ``branch.<name>.rebase`` is set in config; *rebase* will
    cause us to always rebase with ``--preserve-merges``, and *merge* will
    cause us to always merge. If *verbose* is set, additional information is
    printed out for the user.
    """
    def _update_branch(branch):
        """Update a single branch."""
        print(INDENT2, "Updating", branch, end="...")
        upstream = branch.tracking_branch()
        if not upstream:
            print(" skipped; no upstream is tracked.")
            return
        if branch.commit == upstream.commit:
            print(" up to date.")
            return
        branch.checkout()
        c_attr = "branch.{0}.rebase".format(branch.name)
        if not merge and (rebase or repo_rebase or _read_config(repo, c_attr)):
            print(" rebasing...", end="")
            try:
                res = repo.git.rebase(upstream.name)
            except exc.GitCommandError as err:
                print(err)
                ### TODO: ...
            else:
                print(" done.")
        else:
            repo.git.merge(upstream.name)
            ### TODO: etc

    print(INDENT1, BOLD + os.path.split(repo.working_dir)[1] + ":")

    active = repo.active_branch
    if current_only:
        ref = active.tracking_branch()
        if not ref:
            print(INDENT2, ERROR, "no remote tracked by current branch.")
            return
        remotes = [repo.remotes[ref.remote_name]]
    else:
        remotes = repo.remotes
    if not remotes:
        print(INDENT2, ERROR, "no remotes configured to pull from.")
        return

    for remote in remotes:
        print(INDENT2, "Fetching", remote.name, end="...")
        remote.fetch()  ### TODO: show progress
        print(" done.")

    repo_rebase = _read_config(repo, "pull.rebase")

    _update_branch(active)
    branches = set(repo.heads) - {active}
    if branches:
        stashed = repo.git.stash("--all") != "No local changes to save"   ### TODO: don't do this unless actually necessary
        try:
            for branch in sorted(branches, key=lambda b: b.name):
                _update_branch(branch)
        finally:
            active.checkout()
            if stashed:
                repo.git.stash("pop")

def _update_subdirectories(path, long_name, update_args):
    """Update all subdirectories that are git repos in a given directory."""
    repos = []
    for item in os.listdir(path):
        try:
            repo = Repo(os.path.join(path, item))
        except (exc.InvalidGitRepositoryError, exc.NoSuchPathError):
            continue
        repos.append(repo)

    suffix = "ies" if len(repos) != 1 else "y"
    print(long_name[0].upper() + long_name[1:],
          "contains {0} git repositor{1}:".format(len(repos), suffix))
    for repo in sorted(repos, key=lambda r: os.path.split(r.working_dir)[1]):
        _update_repository(repo, *update_args)

def _update_directory(path, update_args, is_bookmark=False):
    """Update a particular directory.

    Determine whether the directory is a git repo on its own, a directory of
    git repositories, or something invalid. If the first, update the single
    repository; if the second, update all repositories contained within; if the
    third, print an error.
    """
    dir_type = "bookmark" if is_bookmark else "directory"
    long_name = dir_type + ' "' + BOLD + path + RESET + '"'

    try:
        repo = Repo(path)
    except exc.NoSuchPathError:
        print(ERROR, long_name, "doesn't exist!")
    except exc.InvalidGitRepositoryError:
        if os.path.isdir(path):
            _update_subdirectories(path, long_name, update_args)
        else:
            print(ERROR, long_name, "isn't a repository!")
    else:
        long_name = (dir_type.capitalize() + ' "' + BOLD + repo.working_dir +
                     RESET + '"')
        print(long_name, "is a git repository:")
        _update_repository(repo, *update_args)

def update_bookmarks(bookmarks, update_args):
    """Loop through and update all bookmarks."""
    if bookmarks:
        for path, name in bookmarks:
            _update_directory(path, update_args, is_bookmark=True)
    else:
        print("You don't have any bookmarks configured! Get help with 'gitup -h'.")

def update_directories(paths, update_args):
    """Update a list of directories supplied by command arguments."""
    for path in paths:
        full_path = os.path.abspath(path)
        _update_directory(full_path, update_args, is_bookmark=False)