#!/usr/bin/env python
# -*- coding: utf-8 -*-

from __future__ import print_function

from argparse import ArgumentParser
import os
import platform
import shutil
import sys


SUPPORTED_SHELLS = ('bash', 'zsh', 'fish')


def cp(src, dest, dryrun=False):
    print("copying file: %s -> %s" % (src, dest))
    if not dryrun:
        shutil.copy(src, dest)


def get_shell():
    return os.path.basename(os.getenv('SHELL', ''))


def mkdir(path, dryrun=False):
    print("creating directory:", path)
    if not dryrun and not os.path.exists(path):
        os.makedirs(path)


def modify_autojump_sh(etc_dir, dryrun=False):
    """Append custom installation path to autojump.sh"""
    custom_install = "\
        \n# check custom install \
        \nif [ -s %s/autojump.${shell} ]; then \
            \n\tsource %s/autojump.${shell} \
        \nfi\n" % (etc_dir, etc_dir)

    with open(os.path.join(etc_dir, 'autojump.sh'), 'a') as f:
        f.write(custom_install)


def parse_arguments():
    default_user_destdir = os.path.join(os.path.expanduser("~"), '.autojump')
    default_user_prefix = ''
    default_user_zshshare = 'functions'
    default_system_destdir = '/'
    default_system_prefix = '/usr/local'
    default_system_zshshare = '/usr/share/zsh/site-functions'

    parser = ArgumentParser(
            description='Installs autojump globally for root users, otherwise \
                    installs in current user\'s home directory.')
    parser.add_argument(
            '-n', '--dryrun', action="store_true", default=False,
            help='simulate installation')
    parser.add_argument(
            '-f', '--force', action="store_true", default=False,
            help='skip root user, shell type, Python version checks')
    parser.add_argument(
            '-d', '--destdir', metavar='DIR', default=default_user_destdir,
            help='set destination to DIR')
    parser.add_argument(
            '-p', '--prefix', metavar='DIR', default=default_user_prefix,
            help='set prefix to DIR')
    parser.add_argument(
            '-z', '--zshshare', metavar='DIR', default=default_user_zshshare,
            help='set zsh share destination to DIR')
    parser.add_argument(
            '-s', '--system', action="store_true", default=False,
            help='install system wide for all users')

    args = parser.parse_args()

    if not args.force:
        if sys.version_info[0] == 2 and sys.version_info[1] < 7:
            print("Python v2.7+ or v3.0+ required.", file=sys.stderr)
            sys.exit(1)

        if get_shell() not in SUPPORTED_SHELLS:
            print("Unsupported shell: %s" % os.getenv('SHELL'),
                  file=sys.stderr)
            sys.exit(1)

        if args.system and os.geteuid() != 0:
            print("Please rerun as root for system-wide installation.",
                  file=sys.stderr)
            sys.exit(1)

    if args.destdir != default_user_destdir \
            or args.prefix != default_user_prefix \
            or args.zshshare != default_user_zshshare:
        args.custom_install = True
    else:
        args.custom_install = False

    if args.system:
        if args.custom_install:
            print("Custom paths incompatible with --system option.",
                  file=sys.stderr)
            sys.exit(1)

        args.destdir = default_system_destdir
        args.prefix = default_system_prefix
        args.zshshare = default_system_zshshare

    return args


def print_post_installation_message(etc_dir):
    if get_shell() == 'fish':
        aj_shell = '%s/autojump.fish' % etc_dir
        source_msg = "if test -f %s; . %s; end" % (aj_shell, aj_shell)

        # TODO(ting|2013-12-31): check config.fish location on OSX
        rcfile = '~/.config/fish/config.fish'
    else:
        aj_shell = '%s/autojump.sh' % etc_dir
        source_msg = "[[ -s %s ]] && source %s" % (aj_shell, aj_shell)

        if platform.system() == 'Darwin' and get_shell() == 'bash':
            rcfile = '~/.profile'
        else:
            rcfile = '~/.%src' % get_shell()

    print("\nPlease manually add the following line to %s:" % rcfile)
    print('\n\t' + source_msg)
    print("\nPlease restart terminal(s) before running autojump.\n")


def main(args):
    if args.dryrun:
        print("\nInstalling autojump to %s (DRYRUN)..." % args.destdir)
    else:
        print("\nInstalling autojump to %s ..." % args.destdir)

    bin_dir = os.path.join(args.destdir, args.prefix, 'bin')
    etc_dir = os.path.join(args.destdir, 'etc/profile.d')
    doc_dir = os.path.join(args.destdir, args.prefix, 'share/man/man1')
    icon_dir = os.path.join(args.destdir, args.prefix, 'share/autojump')
    zshshare_dir = os.path.join(args.destdir, args.zshshare)

    mkdir(bin_dir, args.dryrun)
    mkdir(etc_dir, args.dryrun)
    mkdir(doc_dir, args.dryrun)
    mkdir(icon_dir, args.dryrun)
    mkdir(zshshare_dir, args.dryrun)

    cp('./bin/autojump', bin_dir, args.dryrun)
    cp('./bin/autojump_data.py', bin_dir, args.dryrun)
    cp('./bin/autojump_utils.py', bin_dir, args.dryrun)
    cp('./bin/autojump.sh', etc_dir, args.dryrun)
    cp('./bin/autojump.bash', etc_dir, args.dryrun)
    cp('./bin/autojump.fish', etc_dir, args.dryrun)
    cp('./bin/autojump.zsh', etc_dir, args.dryrun)
    cp('./bin/_j', zshshare_dir, args.dryrun)
    cp('./bin/icon.png', icon_dir, args.dryrun)
    cp('./docs/autojump.1', doc_dir, args.dryrun)

    if args.custom_install:
        modify_autojump_sh(etc_dir, args.dryrun)

    print_post_installation_message(etc_dir)

if __name__ == "__main__":
    sys.exit(main(parse_arguments()))