# Open your $EDITOR to compose a message in weechat
#
# Usage:
# /edit [extension]
# /fenced [extension]
#
# Optional settings:
# /set plugins.var.python.edit.editor "vim -f"
# /set plugins.var.python.edit.terminal "xterm"
# /set plugins.var.python.edit.run_externally "false"
#
# History:
# 10-18-2015
# Version 1.0.2: Add the ability to run the editor in a external terminal
# Version 1.0.1: Add configurable editor key
# Version 1.0.0: initial release

import os
import os.path
import shlex
import subprocess
import weechat

FILE = ""
FENCED = False


def xdg_cache_dir():
    return os.path.expanduser(os.environ.get("XDG_CACHE_HOME", "~/.cache/"))


def weechat_cache_dir():
    cache_dir = os.path.join(xdg_cache_dir(), "weechat")
    if os.path.exists(cache_dir):
        return cache_dir
    return os.path.expanduser(os.environ.get("WEECHAT_HOME", "~/.weechat/"))


def editor_process_cb(data, command, return_code, out, err):
    buf = data

    if return_code != 0:
        cleanup(buf)
        weechat.prnt("", "{}: {}".format(
            err.strip(),
            return_code
        ))
        return weechat.WEECHAT_RC_ERROR

    if return_code == 0:
        read_file(buf)
        cleanup(buf)

    return weechat.WEECHAT_RC_OK


def cleanup(buf):
    try:
        os.remove(FILE)
    except (OSError, IOError):
        pass

    weechat.command(buf, "/window refresh")


def read_file(buf):
    try:
        with open(FILE) as f:
            text = f.read()

        if text and text[-1] == "\n":
            text = text[:-1]  # remove trailing newline if exists.
        if FENCED:
            text = "```\n" + text + "\n```"

        weechat.buffer_set(buf, "input", text)
        weechat.buffer_set(buf, "input_pos", str(len(text)))

    except (OSError, IOError):
        pass

    weechat.command(buf, "/window refresh")


def hook_editor_process(terminal, editor, buf):
    if "{}" in editor:
        editor_cmd = editor.format(FILE)
    else:
        editor_cmd = "{} {}".format(editor, FILE)
    if "{}" in terminal:
        command = terminal.format(editor_cmd)
    else:
        command = "{} -e \"{}\"".format(terminal, editor_cmd)
    weechat.hook_process(command, 0, "editor_process_cb", buf)


def run_blocking(editor, buf):
    cmd = shlex.split(editor) + [FILE]
    code = subprocess.Popen(cmd).wait()

    if code != 0:
        cleanup(buf)

    read_file(buf)


def edit(data, buf, args, fenced=False):
    editor = (weechat.config_get_plugin("editor")
              or os.environ.get("EDITOR", "vim -f"))

    terminal = (weechat.config_get_plugin("terminal")
                or os.getenv("TERMCMD"))

    terminal = terminal or "xterm"

    run_externally = weechat.config_string_to_boolean(
        weechat.config_get_plugin("run_externally")
    )
    run_externally = bool(run_externally)

    global FILE, FENCED

    FILE = os.path.join(weechat_cache_dir(), "message." + ("md" if not args else args))

    FENCED = fenced

    with open(FILE, "w+") as f:
        f.write(weechat.buffer_get_string(buf, "input"))

    if run_externally:
        hook_editor_process(terminal, editor, buf)
    else:
        run_blocking(editor, buf)

    return weechat.WEECHAT_RC_OK


def fenced(data, buf, args):
    return edit(data, buf, args, fenced=True)


def main():
    if not weechat.register("edit", "Keith Smiley", "1.0.0", "MIT",
                            "Open your $EDITOR to compose a message", "", ""):
        return weechat.WEECHAT_RC_ERROR

    weechat.hook_command("edit", "Open your $EDITOR to compose a message",
                         "[extension]",
                         "extension: extension for temporary composing file",
                         "extension", "edit", "")
    weechat.hook_command("fenced", "Open your $EDITOR to compose a message"
                                   " with automatic code fences",
                         "[extension]",
                         "extension: extension for temporary composing file",
                         "extension", "fenced", "")


if __name__ == "__main__":
    main()