#!/usr/bin/env python3

"""
Copyright (c) 2015 Marco Hinz

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
"""

import sys
import os
import subprocess
import textwrap
import argparse

from neovim import attach

class Neovim():
    """Thin wrapper around nvim.attach() for lazy attaching.

    This helps handling the silent and non-silent arguments.
    """
    def __init__(self, sockpath):
        self.sockpath = sockpath
        self.server   = None

    def attached(self, silent=False):
        if self.server is not None:
            return True
        try:
            self.server = attach('socket', path=self.sockpath)
            return True
        except FileNotFoundError:
            if silent:
                return False
            else:
                print("Can't find unix socket {}. Export $NVIM_LISTEN_ADDRESS or use --servername.".format(self.sockpath))
                sys.exit(1)


def parse_args():
    form_class = argparse.RawDescriptionHelpFormatter
    usage      = '{} [arguments]'.format(sys.argv[0])
    epilog     = 'Happy hacking!'
    desc       = textwrap.dedent("""
        Helper tool for nvim that provides --remote and friends.

        All unused arguments will be implicitely fed to --remote-silent.
        Thus the following two lines are equivalent:

            $ nvr --remote-silent foo bar quux
            $ nvr foo bar quux
    """)

    parser = argparse.ArgumentParser(
            formatter_class = form_class,
            usage           = usage,
            epilog          = epilog,
            description     = desc)

    # The following options are similar to their vim equivalents,
    # but work on the remote instance instead.

    parser.add_argument('-l',
            action  = 'store_true',
            help    = 'change to previous window via ":wincmd p"')
    parser.add_argument('-o',
            action  = 'append',
            metavar = '<files>',
            help    = 'open files via ":split"')
    parser.add_argument('-O',
            action  = 'append',
            metavar = '<files>',
            help    = 'open files via ":vsplit"')

    # The following options exactly emulate their vim equivalents.

    parser.add_argument('--remote',
            action  = 'append',
            metavar = '<files>',
            help    = 'open files via ":edit"')
    parser.add_argument('--remote-wait',
            action  = 'append',
            metavar = '<files>',
            help    = 'as --remote')
    parser.add_argument('--remote-silent',
            action  = 'append',
            metavar = '<files>',
            help    = "as --remote, but don't throw error if no server is found")
    parser.add_argument('--remote-wait-silent',
            action  = 'append',
            metavar = '<files>',
            help    = "as --remote, but don't throw error if no server is found")
    parser.add_argument('--remote-tab', '-p',
            action  = 'append',
            metavar = '<files>',
            help    = 'open files via ":tabedit"')
    parser.add_argument('--remote-send',
            action  = 'append',
            metavar = '<keys>',
            help    = 'send key presses')
    parser.add_argument('--remote-expr',
            action  ='append',
            nargs   = '+',
            metavar = '<exprs>',
            help    = 'evaluate expressions in server and print result')
    parser.add_argument('--servername',
            metavar = '<sock>',
            help    = 'path to unix socket (overrides $NVIM_LISTEN_ADDRESS)')
    parser.add_argument('--serverlist',
            action  = 'store_true',
            help    = 'prints socket path to be used')

    return parser.parse_known_args()


def run_nvim(args=[]):
    try:
        # Run interactive shell in case 'nvim' is an alias.
        subprocess.run([os.environ.get('SHELL'), '-ic', 'nvim ' + ' '.join(args)])
    except FileNotFoundError:
        print("Not in $PATH: nvim")
        sys.exit(1)


def main():
    args, unused = parse_args()
    sockpath = os.environ.get('NVIM_LISTEN_ADDRESS')

    if args.servername:
        sockpath = args.servername
        if len(list(filter(lambda x: x is not None, vars(args).values()))) == 1:
            os.environ['NVIM_LISTEN_ADDRESS'] = sockpath
            run_nvim()
    else:
        if sockpath is None:
            sockpath = '/tmp/nvimsocket'

    if args.serverlist:
        if sockpath is not None:
            print(sockpath)

    n = Neovim(sockpath)

    if args.l and n.attached(silent=True):
        n.server.command('wincmd p', async=True)

    if args.remote_silent and n.attached(silent=True):
        for fname in args.remote_silent:
            n.server.command('edit {}'.format(fname.replace(" ", "\ ")), async=True)

    if args.remote_wait_silent and n.attached(silent=True):
        for fname in args.remote_wait_silent:
            n.server.command('edit {}'.format(fname.replace(" ", "\ ")))

    if args.remote and n.attached():
        for fname in args.remote:
            n.server.command('edit {}'.format(fname.replace(" ", "\ ")), async=True)

    if args.remote_wait and n.attached():
        for fname in args.remote_wait:
            n.server.command('edit {}'.format(fname.replace(" ", "\ ")))

    if args.remote_tab and n.attached():
        for fname in args.remote_tab:
            n.server.command('tabedit {}'.format(fname.replace(" ", "\ ")))

    if args.remote_send and n.attached():
        for keys in args.remote_send:
            n.server.input(keys)

    if args.remote_expr and n.attached():
        for expr in args.remote_expr[0]:
            result = ''
            try:
                result = n.server.eval(expr)
            except:
                print('Evaluation failed: ' + expr)
                continue
            if type(result) is bytes:
                print(result.decode())
            elif type(result) is list:
                print(list(map(lambda x: x.decode() if type(x) is bytes else x, result)))
            elif type(result) is dict:
                print({ (k.decode() if type(k) is bytes else k): v for (k,v) in result.items() })
            else:
                print(result)

    if args.o and n.attached():
        for fname in args.o:
            n.server.command('split {}'.format(fname.replace(" ", "\ ")), async=True)

    if args.O and n.attached():
        for fname in args.O:
            n.server.command('vsplit {}'.format(fname.replace(" ", "\ ")), async=True)

    if unused and n.attached(silent=True):
        for fname in unused:
            n.server.command('edit {}'.format(fname.replace(" ", "\ ")), async=True)


if __name__ == '__main__':
    main()