#
# SPDX-FileCopyrightText: 2009-2026 Sébastien Helleu <flashcode@flashtux.org>
# SPDX-FileCopyrightText: 2010 m4v <lambdae2@gmail.com>
# SPDX-FileCopyrightText: 2011 stfn <stfnmd@googlemail.com>
# SPDX-FileCopyrightText: 2025 Leo Vivier <zaeph@zaeph.net>
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

"""Quick jump to buffers."""

import re
from typing import Any

SCRIPT_NAME = "go"
SCRIPT_AUTHOR = "Sébastien Helleu <flashcode@flashtux.org>"
SCRIPT_VERSION = "3.1.1"
SCRIPT_LICENSE = "GPL3"
SCRIPT_DESC = "Quick jump to buffers"

SCRIPT_COMMAND = "go"

IMPORT_OK = True

try:
    import weechat  # type: ignore[import]
except ImportError:
    print("This script must be run under WeeChat.")
    print("Get WeeChat now at: https://weechat.org/")
    IMPORT_OK = False

# script options
SETTINGS = {
    "auto_jump": ("off", "automatically jump to buffer when it is uniquely selected"),
    "buffer_number": ("on", "display buffer number"),
    "color_number": ("yellow,magenta", "color for buffer number (not selected)"),
    "color_number_selected": ("yellow,red", "color for selected buffer number"),
    "color_name": ("black,cyan", "color for buffer name (not selected)"),
    "color_name_selected": ("black,brown", "color for a selected buffer name"),
    "color_name_highlight": (
        "red,cyan",
        "color for highlight in buffer name (not selected)",
    ),
    "color_name_highlight_selected": (
        "red,brown",
        "color for highlight in a selected buffer name",
    ),
    "regexp_search": ("off", "search buffer matches using regexps"),
    "fuzzy_search": ("off", "search buffer matches using approximation"),
    "message": ("Go to: ", "message to display before list of buffers"),
    "min_chars": ("0", "Minimum chars to search and display list of matching buffers"),
    "short_name": ("off", "display and search in short names instead of buffer name"),
    "short_name_server": (
        "off",
        "prefix short names with server names for search and display",
    ),
    "sort": (
        "number,beginning",
        "comma-separated list of keys to sort buffers "
        "(the order is important, sorts are performed in the given order): "
        "name = sort by name (or short name), ",
        "hotlist = sort by hotlist order, "
        "number = first match a buffer number before digits in name, "
        "beginning = first match at beginning of names (or short names); "
        "the default sort of buffers is by numbers",
    ),
    "use_core_instead_weechat": (
        "off",
        'use name "core" instead of "weechat" for core buffer',
    ),
}

# hooks management
HOOK_COMMAND_RUN = {
    "input": ("/input *", "go_command_run_input"),
    "buffer": ("/buffer *", "go_command_run_buffer"),
    "window": ("/window *", "go_command_run_window"),
}
hooks = {}

# input before command /go (we'll restore it later)
saved_input = ""
saved_input_pos = 0

# last user input (if changed, we'll update list of matching buffers)
old_input = None

# matching buffers
buffers = []
buffers_pos = 0


def go_option_enabled(option: str) -> bool:
    """Check if a boolean script option is enabled or not."""
    return weechat.config_string_to_boolean(weechat.config_get_plugin(option))


def go_info_running(_data: str, _info_name: str, _arguments: str) -> str:
    """Return "1" if go is running, otherwise "0"."""
    return "1" if "modifier" in hooks else "0"


def go_unhook_one(hook: str) -> None:
    """Unhook something hooked by this script."""
    global hooks
    if hook in hooks:
        weechat.unhook(hooks[hook])
        del hooks[hook]


def go_unhook_all() -> None:
    """Unhook all."""
    go_unhook_one("modifier")
    for hook in HOOK_COMMAND_RUN:
        go_unhook_one(hook)
    weechat.bar_item_update("input_text")


def go_hook_all() -> None:
    """Hook command_run and modifier."""
    global hooks
    priority = ""
    version = weechat.info_get("version_number", "") or 0
    # use high priority for hook to prevent conflict with other plugins/scripts
    # (WeeChat >= 0.3.4 only)
    if int(version) >= 0x00030400:
        priority = "2000|"
    for hook, value in HOOK_COMMAND_RUN.items():
        if hook not in hooks:
            hooks[hook] = weechat.hook_command_run(
                "%s%s" % (priority, value[0]), value[1], ""
            )
    if "modifier" not in hooks:
        hooks["modifier"] = weechat.hook_modifier(
            "input_text_display_with_cursor", "go_input_modifier", ""
        )
        weechat.bar_item_update("input_text")


def go_start(buf: str) -> None:
    """Start go on buffer."""
    global saved_input, saved_input_pos, old_input, buffers_pos
    go_hook_all()
    saved_input = weechat.buffer_get_string(buf, "input")
    saved_input_pos = weechat.buffer_get_integer(buf, "input_pos")
    weechat.buffer_set(buf, "input", "")
    old_input = None
    buffers_pos = 0


def go_end(buf: str) -> None:
    """End go on buffer."""
    global saved_input, saved_input_pos, old_input
    go_unhook_all()
    weechat.buffer_set(buf, "input", saved_input)
    weechat.buffer_set(buf, "input_pos", str(saved_input_pos))
    old_input = None


def go_match_beginning(buf: str, string: str) -> bool:
    """Check if a string matches the beginning of buffer name/short name."""
    if not string:
        return False
    esc_str = re.escape(string)
    if re.search(r"^#?" + esc_str, buf["name"]) or re.search(
        r"^#?" + esc_str, buf["short_name"]
    ):
        return True
    return False


def go_match_fuzzy(name: str, string: str) -> bool:
    """Check if string matches name using approximation."""
    if not string:
        return False

    name_len = len(name)
    string_len = len(string)

    if string_len > name_len:
        return False
    if name_len == string_len:
        return name == string

    # Attempt to match all chars somewhere in name
    prev_index = -1
    for i, char in enumerate(string):
        index = name.find(char, prev_index + 1)
        if index == -1:
            return False
        prev_index = index
    return True


def go_now(buf: str, args: str) -> None:
    """Go to buffer specified by args."""
    listbuf = go_matching_buffers(args)
    if not listbuf:
        return

    # prefer buffer that matches at beginning (if option is enabled)
    if "beginning" in weechat.config_get_plugin("sort").split(","):
        for index in range(len(listbuf)):
            if go_match_beginning(listbuf[index], args):
                weechat.command(buf, "/buffer " + str(listbuf[index]["full_name"]))
                return

    # jump to first buffer in matching buffers by default
    weechat.command(buf, "/buffer " + str(listbuf[0]["full_name"]))


def go_cmd(_data: str, buf: str, args: str) -> int:
    """Command "/go": just hook what we need."""
    global hooks
    if args:
        go_now(buf, args)
    elif "modifier" in hooks:
        go_end(buf)
    else:
        go_start(buf)
    return weechat.WEECHAT_RC_OK


def go_matching_buffers(strinput: str) -> list[dict[str, Any]]:
    """Return a list with buffers matching user input."""
    global buffers_pos
    listbuf = []
    if len(strinput) == 0:
        buffers_pos = 0
    strinput = strinput.lower()
    infolist = weechat.infolist_get("buffer", "", "")
    while weechat.infolist_next(infolist):
        pointer = weechat.infolist_pointer(infolist, "pointer")
        short_name = weechat.infolist_string(infolist, "short_name")
        server = weechat.buffer_get_string(pointer, "localvar_server")
        if go_option_enabled("short_name"):
            if go_option_enabled("short_name_server") and server:
                name = server + "." + short_name
            else:
                name = short_name
        else:
            name = weechat.infolist_string(infolist, "name")
        if (
            name == "weechat"
            and go_option_enabled("use_core_instead_weechat")
            and weechat.infolist_string(infolist, "plugin_name") == "core"
        ):
            name = "core"
        number = weechat.infolist_integer(infolist, "number")
        full_name = weechat.infolist_string(infolist, "full_name")
        if not full_name:
            full_name = "%s.%s" % (
                weechat.infolist_string(infolist, "plugin_name"),
                weechat.infolist_string(infolist, "name"),
            )
        if go_option_enabled("regexp_search"):
            matching = bool(re.search(strinput, name, re.IGNORECASE))
        else:
            matching = name.lower().find(strinput) >= 0
        if not matching and strinput[-1] == " ":
            matching = name.lower().endswith(strinput.strip())
        if not matching and go_option_enabled("fuzzy_search"):
            matching = go_match_fuzzy(name.lower(), strinput)
        if not matching and strinput.isdigit():
            matching = str(number).startswith(strinput)
        if len(strinput) == 0 or matching:
            listbuf.append(
                {
                    "number": number,
                    "short_name": short_name,
                    "name": name,
                    "full_name": full_name,
                    "pointer": pointer,
                }
            )
    weechat.infolist_free(infolist)

    # sort buffers
    hotlist = []
    infolist = weechat.infolist_get("hotlist", "", "")
    while weechat.infolist_next(infolist):
        hotlist.append(weechat.infolist_pointer(infolist, "buffer_pointer"))
    weechat.infolist_free(infolist)
    last_index_hotlist = len(hotlist)

    def _sort_name(buf):
        """Sort buffers by name (or short name)."""
        return buf["name"]

    def _sort_hotlist(buf):
        """Sort buffers by hotlist order."""
        try:
            return hotlist.index(buf["pointer"])
        except ValueError:
            # not in hotlist, always last.
            return last_index_hotlist

    def _sort_match_number(buf):
        """Sort buffers by match on number."""
        return 0 if str(buf["number"]) == strinput else 1

    def _sort_match_beginning(buf):
        """Sort buffers by match at beginning."""
        return 0 if go_match_beginning(buf, strinput) else 1

    funcs = {
        "name": _sort_name,
        "hotlist": _sort_hotlist,
        "number": _sort_match_number,
        "beginning": _sort_match_beginning,
    }

    for key in weechat.config_get_plugin("sort").split(","):
        if key in funcs:
            listbuf = sorted(listbuf, key=funcs[key])

    if not strinput:
        index = [
            i
            for i, buf in enumerate(listbuf)
            if buf["pointer"] == weechat.current_buffer()
        ]
        if index:
            buffers_pos = index[0]

    return listbuf


def go_buffers_to_string(listbuf: list[dict[str, Any]], pos: int, strinput: str) -> str:
    """Return string built with list of buffers found (matching user input)."""
    try:
        if len(strinput) < int(weechat.config_get_plugin("min_chars")):
            return ""
    except ValueError:
        pass
    string = ""
    strinput = strinput.lower()
    for i in range(len(listbuf)):
        selected = "_selected" if i == pos else ""
        buffer_name = listbuf[i]["name"]
        index = buffer_name.lower().find(strinput)
        if index >= 0:
            index2 = index + len(strinput)
            name = "%s%s%s%s%s" % (
                buffer_name[:index],
                weechat.color(
                    weechat.config_get_plugin("color_name_highlight" + selected)
                ),
                buffer_name[index:index2],
                weechat.color(weechat.config_get_plugin("color_name" + selected)),
                buffer_name[index2:],
            )
        elif go_option_enabled("fuzzy_search") and go_match_fuzzy(
            buffer_name.lower(), strinput
        ):
            name = ""
            prev_index = -1
            for char in strinput.lower():
                index = buffer_name.lower().find(char, prev_index + 1)
                if prev_index < 0:
                    name += buffer_name[:index]
                    name += weechat.color(
                        weechat.config_get_plugin("color_name_highlight" + selected)
                    )
                if prev_index >= 0 and index > prev_index + 1:
                    name += weechat.color(
                        weechat.config_get_plugin("color_name" + selected)
                    )
                    name += buffer_name[prev_index + 1 : index]
                    name += weechat.color(
                        weechat.config_get_plugin("color_name_highlight" + selected)
                    )
                name += buffer_name[index]
                prev_index = index

            name += weechat.color(weechat.config_get_plugin("color_name" + selected))
            name += buffer_name[prev_index + 1 :]
        else:
            name = buffer_name
        string += " "
        if go_option_enabled("buffer_number"):
            string += "%s%s" % (
                weechat.color(weechat.config_get_plugin("color_number" + selected)),
                str(listbuf[i]["number"]),
            )
        string += "%s%s%s" % (
            weechat.color(weechat.config_get_plugin("color_name" + selected)),
            name,
            weechat.color("reset"),
        )
    return "  " + string if string else ""


def go_input_modifier(_data: str, _modifier: str, modifier_data: str, string: str) -> str:
    """This modifier is called when input text item is built by WeeChat.

    This is commonly called after changes in input or cursor move: it builds
    a new input with prefix ("Go to:"), and suffix (list of buffers found).
    """
    global old_input, buffers, buffers_pos
    if modifier_data != weechat.current_buffer():
        return ""
    names = ""
    new_input = weechat.string_remove_color(string, "")
    new_input = new_input.lstrip()
    if old_input is None or new_input != old_input:
        old_buffers = buffers
        buffers = go_matching_buffers(new_input)
        if buffers != old_buffers and len(new_input) > 0:
            if len(buffers) == 1 and go_option_enabled("auto_jump"):
                weechat.command(modifier_data, "/wait 1ms /input return")
            buffers_pos = 0
        old_input = new_input
    names = go_buffers_to_string(buffers, buffers_pos, new_input.strip())
    return weechat.config_get_plugin("message") + string + names


def go_command_run_input(_data: str, buf: str, command: str) -> int:
    """Function called when a command "/input xxx" is run."""
    global buffers, buffers_pos
    if command.startswith("/input search_text") or command.startswith("/input jump"):
        # search text or jump to another buffer is forbidden now
        return weechat.WEECHAT_RC_OK_EAT
    elif command == "/input complete_next":
        # choose next buffer in list
        buffers_pos += 1
        if buffers_pos >= len(buffers):
            buffers_pos = 0
        weechat.hook_signal_send(
            "input_text_changed", weechat.WEECHAT_HOOK_SIGNAL_POINTER, buf
        )
        return weechat.WEECHAT_RC_OK_EAT
    elif command == "/input complete_previous":
        # choose previous buffer in list
        buffers_pos -= 1
        if buffers_pos < 0:
            buffers_pos = len(buffers) - 1
        weechat.hook_signal_send(
            "input_text_changed", weechat.WEECHAT_HOOK_SIGNAL_POINTER, buf
        )
        return weechat.WEECHAT_RC_OK_EAT
    elif command == "/input return":
        # switch to selected buffer (if any)
        go_end(buf)
        if len(buffers) > 0:
            weechat.command(buf, "/buffer " + str(buffers[buffers_pos]["full_name"]))
        return weechat.WEECHAT_RC_OK_EAT
    return weechat.WEECHAT_RC_OK


def go_command_run_buffer(_data: str, _buf: str, _command: str) -> int:
    """Function called when a command "/buffer xxx" is run."""
    return weechat.WEECHAT_RC_OK_EAT


def go_command_run_window(_data: str, buf: str, command: str) -> int:
    """Function called when a command "/window xxx" is run."""
    if command == "/window scroll_bottom":
        # cancel selection and return to input
        go_end(buf)
        return weechat.WEECHAT_RC_OK_EAT
    return weechat.WEECHAT_RC_OK_EAT


def go_unload_script() -> int:
    """Function called when script is unloaded."""
    go_unhook_all()
    return weechat.WEECHAT_RC_OK


def go_main() -> None:
    """Entry point."""
    if not weechat.register(
        SCRIPT_NAME,
        SCRIPT_AUTHOR,
        SCRIPT_VERSION,
        SCRIPT_LICENSE,
        SCRIPT_DESC,
        "go_unload_script",
        "",
    ):
        return
    weechat.hook_command(
        SCRIPT_COMMAND,
        "Quick jump to buffers",
        "[name]",
        "name: directly jump to buffer by name (without argument, list is "
        "displayed)\n\n"
        "You can bind command to a key, for example:\n"
        "  /key bind meta-g /go\n\n"
        "You can use completion key (commonly Tab and shift-Tab) to select "
        "next/previous buffer in list.",
        "%(buffers_names)",
        "go_cmd",
        "",
    )

    # set default settings
    version = weechat.info_get("version_number", "") or 0
    for option, value in SETTINGS.items():
        if not weechat.config_is_set_plugin(option):
            weechat.config_set_plugin(option, value[0])
        if int(version) >= 0x00030500:
            weechat.config_set_desc_plugin(
                option, '%s (default: "%s")' % (value[1], value[0])
            )
    weechat.hook_info(
        "go_running",
        'Return "1" if go is running, otherwise "0"',
        "",
        "go_info_running",
        "",
    )


if __name__ == "__main__" and IMPORT_OK:
    go_main()