"""
Get interface description of GRASS commands

Based on gui/wxpython/gui_modules/menuform.py

Usage:

::

    from grass.script import task as gtask

    gtask.command_info("r.info")

(C) 2011 by the GRASS Development Team
This program is free software under the GNU General Public
License (>=v2). Read the file COPYING that comes with GRASS
for details.

.. sectionauthor:: Martin Landa <landa.martin gmail.com>
"""

import os
import re
import sys
import keyword
import xml.etree.ElementTree as ET
from xml.parsers import expat

from grass.exceptions import ScriptError
from .utils import decode, split
from .core import Popen, PIPE, get_real_command

ETREE_EXCEPTIONS = (ET.ParseError, expat.ExpatError)


class grassTask:
    """This class holds the structures needed for filling by the parser

    Parameter blackList is a dictionary with fixed structure, eg.

    ::

        blackList = {
            "items": {"d.legend": {"flags": ["m"], "params": []}},
            "enabled": True,
        }

    :param str path: full path
    :param blackList: hide some options in the GUI (dictionary)
    """

    def __init__(self, path=None, blackList=None):
        self.path = path
        self.name = _("unknown")
        self.params = []
        self.description = ""
        self.label = ""
        self.flags = []
        self.keywords = []
        self.errorMsg = ""
        self.firstParam = None
        if blackList:
            self.blackList = blackList
        else:
            self.blackList = {"enabled": False, "items": {}}

        if path is not None:
            try:
                processTask(
                    tree=ET.fromstring(get_interface_description(path)), task=self
                )
            except ScriptError as e:
                self.errorMsg = e.value

            self.define_first()

    def define_first(self):
        """Define first parameter

        :return: name of first parameter
        """
        if len(self.params) > 0:
            self.firstParam = self.params[0]["name"]

        return self.firstParam

    def get_error_msg(self):
        """Get error message ('' for no error)"""
        return self.errorMsg

    def get_name(self):
        """Get task name"""
        if sys.platform != "win32":
            return self.name

        name, ext = os.path.splitext(self.name)
        if ext in {".py", ".sh"}:
            return name
        return self.name

    def get_description(self, full=True):
        """Get module's description

        :param bool full: True for label + desc
        """
        if not self.label:
            return self.description
        if full:
            return self.label + " " + self.description
        return self.label

    def get_keywords(self):
        """Get module's keywords"""
        return self.keywords

    def get_list_params(self, element="name"):
        """Get list of parameters

        :param str element: element name
        """
        return [p[element] for p in self.params]

    def get_list_flags(self, element="name"):
        """Get list of flags

        :param str element: element name
        """
        return [p[element] for p in self.flags]

    def get_param(self, value, element="name", raiseError=True):
        """Find and return a param by name

        :param value: param's value
        :param str element: element name
        :param bool raiseError: True for raise on error
        """
        for p in self.params:
            val = p.get(element, None)
            if val is None:
                continue
            if isinstance(val, (list, tuple)):
                if value in val:
                    return p
            elif p[element] == value:
                return p

        if raiseError:
            raise ValueError(
                _("Parameter element '%(element)s' not found: '%(value)s'")
                % {"element": element, "value": value}
            )
        return None

    def get_flag(self, aFlag):
        """Find and return a flag by name

        Raises ValueError when the flag is not found.

        :param str aFlag: name of the flag
        :raises ValueError: When the flag is not found.
        """
        for f in self.flags:
            if f["name"] == aFlag:
                return f
        raise ValueError(_("Flag not found: %s") % aFlag)

    def get_cmd_error(self) -> list[str]:
        """Get error string produced by get_cmd(ignoreErrors = False)

        :return: list of errors
        """
        errorList = []
        # determine if suppress_required flag is given
        for f in self.flags:
            if f["value"] and f["suppress_required"]:
                return errorList

        for p in self.params:
            if not p.get("value", "") and p.get("required", False):
                if not p.get("default", ""):
                    desc = p.get("label", "")
                    if not desc:
                        desc = p["description"]
                    errorList.append(
                        _("Parameter '%(name)s' (%(desc)s) is missing.")
                        % {"name": p["name"], "desc": desc}
                    )

        return errorList

    def get_cmd(self, ignoreErrors=False, ignoreRequired=False, ignoreDefault=True):
        """Produce an array of command name and arguments for feeding
        into some execve-like command processor.

        :param bool ignoreErrors: True to return whatever has been built so
                                  far, even though it would not be a correct
                                  command for GRASS
        :param bool ignoreRequired: True to ignore required flags, otherwise
                                    '@<required@>' is shown
        :param bool ignoreDefault: True to ignore parameters with default values

        :raises ValueError: When ``ignoreErrors=False`` and there are errors
        """
        cmd = [self.get_name()]

        suppress_required = False
        for flag in self.flags:
            if flag["value"]:
                if len(flag["name"]) > 1:  # e.g. overwrite
                    cmd += ["--" + flag["name"]]
                else:
                    cmd += ["-" + flag["name"]]
                if flag["suppress_required"]:
                    suppress_required = True
        for p in self.params:
            if p.get("value", "") == "" and p.get("required", False):
                if p.get("default", "") != "":
                    cmd += ["%s=%s" % (p["name"], p["default"])]
                elif ignoreErrors and not suppress_required and not ignoreRequired:
                    cmd += ["%s=%s" % (p["name"], _("<required>"))]
            elif (
                p.get("value", "") == ""
                and p.get("default", "") != ""
                and not ignoreDefault
            ):
                cmd += ["%s=%s" % (p["name"], p["default"])]
            elif p.get("value", "") != "" and (
                p["value"] != p.get("default", "") or not ignoreDefault
            ):
                # output only values that have been set, and different from defaults
                cmd += ["%s=%s" % (p["name"], p["value"])]

        errList = self.get_cmd_error()
        if ignoreErrors is False and errList:
            raise ValueError("\n".join(errList))

        return cmd

    def get_options(self):
        """Get options"""
        return {"flags": self.flags, "params": self.params}

    def has_required(self):
        """Check if command has at least one required parameter"""
        return any(p.get("required", False) for p in self.params)

    def set_param(self, aParam, aValue, element="value"):
        """Set param value/values."""
        try:
            param = self.get_param(aParam)
        except ValueError:
            return

        param[element] = aValue

    def set_flag(self, aFlag, aValue, element="value"):
        """Enable / disable flag."""
        try:
            param = self.get_flag(aFlag)
        except ValueError:
            return

        param[element] = aValue

    def set_options(self, opts):
        """Set flags and parameters

        :param opts list of flags and parameters"""
        for opt in opts:
            if opt[0] == "-":  # flag
                self.set_flag(opt.lstrip("-"), True)
            else:  # parameter
                key, value = opt.split("=", 1)
                self.set_param(key, value)


class processTask:
    """A ElementTree handler for the --interface-description output,
    as defined in grass-interface.dtd. Extend or modify this and the
    DTD if the XML output of GRASS' parser is extended or modified.

    :param tree: root tree node
    :param task: grassTask instance or None
    :param blackList: list of flags/params to hide

    :return: grassTask instance
    """

    def __init__(self, tree, task=None, blackList=None):
        if task:
            self.task = task
        else:
            self.task = grassTask()
        if blackList:
            self.task.blackList = blackList

        self.root = tree

        self._process_module()
        self._process_params()
        self._process_flags()
        self.task.define_first()

    def _process_module(self):
        """Process module description"""
        self.task.name = self.root.get("name", default="unknown")

        # keywords
        for kw in self._get_node_text(self.root, "keywords").split(","):
            self.task.keywords.append(kw.strip())

        self.task.label = self._get_node_text(self.root, "label")
        self.task.description = self._get_node_text(self.root, "description")

    def _process_params(self) -> None:
        """Process parameters"""
        for p in self.root.findall("parameter"):
            # gisprompt
            node_gisprompt = p.find("gisprompt")
            gisprompt = False
            age = element = prompt = None
            if node_gisprompt is not None:
                gisprompt = True
                age = node_gisprompt.get("age", "")
                element = node_gisprompt.get("element", "")
                prompt = node_gisprompt.get("prompt", "")

            # value(s)
            values = []
            values_desc = []
            node_values = p.find("values")
            if node_values is not None:
                for pv in node_values.findall("value"):
                    values.append(self._get_node_text(pv, "name"))
                    desc = self._get_node_text(pv, "description")
                    if desc:
                        values_desc.append(desc)

            # keydesc
            key_desc = []
            node_key_desc = p.find("keydesc")
            if node_key_desc is not None:
                for ki in node_key_desc.findall("item"):
                    key_desc.append(ki.text)

            multiple = p.get("multiple", "no") == "yes"
            required = p.get("required", "no") == "yes"

            hidden: bool = bool(
                self.task.blackList["enabled"]
                and self.task.get_name() in self.task.blackList["items"]
                and p.get("name")
                in self.task.blackList["items"][self.task.get_name()].get("params", [])
            )

            self.task.params.append(
                {
                    "name": p.get("name"),
                    "type": p.get("type"),
                    "required": required,
                    "multiple": multiple,
                    "label": self._get_node_text(p, "label"),
                    "description": self._get_node_text(p, "description"),
                    "gisprompt": gisprompt,
                    "age": age,
                    "element": element,
                    "prompt": prompt,
                    "guisection": self._get_node_text(p, "guisection"),
                    "guidependency": self._get_node_text(p, "guidependency"),
                    "default": self._get_node_text(p, "default"),
                    "values": values,
                    "values_desc": values_desc,
                    "value": "",
                    "key_desc": key_desc,
                    "hidden": hidden,
                }
            )

    def _process_flags(self) -> None:
        """Process flags"""
        for p in self.root.findall("flag"):
            hidden: bool = bool(
                self.task.blackList["enabled"]
                and self.task.name in self.task.blackList["items"]
                and p.get("name")
                in self.task.blackList["items"][self.task.name].get("flags", [])
            )

            suppress_required: bool = bool(p.find("suppress_required") is not None)

            self.task.flags.append(
                {
                    "name": p.get("name"),
                    "label": self._get_node_text(p, "label"),
                    "description": self._get_node_text(p, "description"),
                    "guisection": self._get_node_text(p, "guisection"),
                    "suppress_required": suppress_required,
                    "value": False,
                    "hidden": hidden,
                }
            )

    def _get_node_text(self, node, tag, default=""):
        """Get node text"""
        p = node.find(tag)
        if p is not None:
            return " ".join(p.text.split())

        return default

    def get_task(self):
        """Get grassTask instance"""
        return self.task


def convert_xml_to_utf8(xml_text):
    # enc = locale.getdefaultlocale()[1]
    if xml_text is None:
        return None
    # modify: fetch encoding from the interface description text(xml)
    # e.g. <?xml version="1.0" encoding="GBK"?>
    pattern = re.compile(rb'<\?xml[^>]*\Wencoding="([^"]*)"[^>]*\?>')
    m = re.match(pattern, xml_text)
    if m is None:
        try:
            xml_text.decode("utf-8", errors="strict")
            return xml_text
        except UnicodeDecodeError:
            return decode(xml_text).encode("utf-8")

    enc = m.groups()[0]

    # modify: change the encoding to "utf-8", for correct parsing
    xml_text_utf8 = xml_text.decode(enc.decode("ascii")).encode("utf-8")
    p = re.compile(b'encoding="' + enc + b'"', re.IGNORECASE)
    return p.sub(b'encoding="utf-8"', xml_text_utf8)


def get_interface_description(cmd):
    """Returns the XML description for the GRASS cmd (force text encoding to
    "utf-8").

    The DTD must be located in $GISBASE/gui/xml/grass-interface.dtd,
    otherwise the parser will not succeed.

    :param cmd: command (name of GRASS module)
    :raises ~grass.exceptions.ScriptError:
        When unable to fetch the interface description for a command.
    """
    try:
        p = Popen(
            [cmd, "--interface-description"], stdout=PIPE, stderr=PIPE, text=False
        )
        cmdout, cmderr = p.communicate()

        # TODO: do it better (?)
        if not cmdout and sys.platform == "win32":
            # we in fact expect pure module name (without extension)
            # so, lets remove extension
            if cmd.endswith(".py"):
                cmd = os.path.splitext(cmd)[0]

            if cmd == "d.rast3d":
                sys.path.insert(0, os.path.join(os.getenv("GISBASE"), "gui", "scripts"))

            p = Popen(
                [sys.executable, get_real_command(cmd), "--interface-description"],
                stdout=PIPE,
                stderr=PIPE,
                text=False,
            )
            cmdout, cmderr = p.communicate()

            if cmd == "d.rast3d":
                del sys.path[0]  # remove gui/scripts from the path

        if p.returncode != 0:
            raise ScriptError(
                _(
                    "Unable to fetch interface description for command '<{cmd}>'."
                    "\n\nDetails: <{det}>"
                ).format(cmd=cmd, det=decode(cmderr))
            )

    except OSError as e:
        raise ScriptError(
            _(
                "Unable to fetch interface description for command '<{cmd}>'."
                "\n\nDetails: <{det}>"
            ).format(cmd=cmd, det=e)
        )

    desc = convert_xml_to_utf8(cmdout)
    return desc.replace(
        b"grass-interface.dtd",
        os.path.join(os.getenv("GISBASE"), "gui", "xml", "grass-interface.dtd").encode(
            "utf-8"
        ),
    )


def parse_interface(name, parser=processTask, blackList=None):
    """Parse interface of given GRASS module

    The *name* is either GRASS module name (of a module on path) or
    a full or relative path to an executable.

    :param str name: name of GRASS module to be parsed
    :param parser:
    :param blackList:

    :raises ~grass.exceptions.ScriptError:
        When the interface description of a module cannot be parsed.
    """
    try:
        tree = ET.fromstring(get_interface_description(name))
    except ETREE_EXCEPTIONS as error:
        raise ScriptError(
            _("Cannot parse interface description of <{name}> module: {error}").format(
                name=name, error=error
            )
        )
    task = parser(tree, blackList=blackList).get_task()
    # if name from interface is different than the originally
    # provided name, then the provided name is likely a full path needed
    # to actually run the module later
    # (processTask uses only the XML which does not contain the original
    # path used to execute the module)
    if task.name != name:
        task.path = name
    return task


def command_info(cmd):
    """Returns meta information for any GRASS command as dictionary
    with entries for description, keywords, usage, flags, and
    parameters, e.g.

    >>> command_info("g.tempfile")  # doctest: +NORMALIZE_WHITESPACE
    {'keywords': ['general', 'support'], 'params': [{'gisprompt': False,
    'multiple': False, 'name': 'pid', 'guidependency': '', 'default': '',
    'age': None, 'required': True, 'value': '', 'label': '', 'guisection': '',
    'key_desc': [], 'values': [], 'values_desc': [], 'prompt': None,
    'hidden': False, 'element': None, 'type': 'integer', 'description':
    'Process id to use when naming the tempfile'}], 'flags': [{'description':
    "Dry run - don't create a file, just prints it's file name", 'value':
    False, 'label': '', 'guisection': '', 'suppress_required': False,
    'hidden': False, 'name': 'd'}, {'description': 'Print usage summary',
    'value': False, 'label': '', 'guisection': '', 'suppress_required': False,
    'hidden': False, 'name': 'help'}, {'description': 'Verbose module output',
    'value': False, 'label': '', 'guisection': '', 'suppress_required': False,
    'hidden': False, 'name': 'verbose'}, {'description': 'Quiet module output',
    'value': False, 'label': '', 'guisection': '', 'suppress_required': False,
    'hidden': False, 'name': 'quiet'}], 'description': "Creates a temporary
    file and prints it's file name.", 'usage': 'g.tempfile pid=integer [--help]
    [--verbose] [--quiet]'}

    >>> command_info("v.buffer")
    ['vector', 'geometry', 'buffer']

    :param str cmd: the command to query
    """
    task = parse_interface(cmd)
    flags = task.get_options()["flags"]
    params = task.get_options()["params"]
    cmdinfo = {
        "description": task.get_description(),
        "keywords": task.get_keywords(),
        "flags": flags,
        "params": params,
    }

    usage = task.get_name()
    flags_short = []
    flags_long = []
    for f in flags:
        fname = f.get("name", "unknown")
        if len(fname) > 1:
            flags_long.append(fname)
        else:
            flags_short.append(fname)

    if len(flags_short) > 1:
        usage += " [-" + "".join(flags_short) + "]"

    for p in params:
        ptype = ",".join(p.get("key_desc", []))
        if not ptype:
            ptype = p.get("type", "")
        req = p.get("required", False)
        if not req:
            usage += " ["
        else:
            usage += " "
        usage += p["name"] + "=" + ptype
        if p.get("multiple", False):
            usage += "[," + ptype + ",...]"
        if not req:
            usage += "]"

    for key in flags_long:
        usage += " [--" + key + "]"

    cmdinfo["usage"] = usage

    return cmdinfo


def cmdtuple_to_list(cmd):
    """Convert command tuple to list.

    :param tuple cmd: GRASS command to be converted

    :return: command in list
    """
    cmdList = []
    if not cmd:
        return cmdList

    cmdList.append(cmd[0])

    if "flags" in cmd[1]:
        for flag in cmd[1]["flags"]:
            cmdList.append("-" + flag)
    for flag in ("help", "verbose", "quiet", "overwrite"):
        if flag in cmd[1] and cmd[1][flag] is True:
            cmdList.append("--" + flag)

    for k, v in cmd[1].items():
        if k in {"flags", "help", "verbose", "quiet", "overwrite"}:
            continue
        if " " in v:
            v = '"%s"' % v
        cmdList.append("%s=%s" % (k, v))

    return cmdList


def cmdlist_to_tuple(cmd):
    """Convert command list to tuple for run_command() and others

    :param list cmd: GRASS command to be converted

    :return: command as tuple
    """
    if len(cmd) < 1:
        return None

    dcmd = {}
    for item in cmd[1:]:
        if "=" in item:  # params
            key, value = item.split("=", 1)
            dcmd[str(key)] = value.replace('"', "")
        elif item[:2] == "--":  # long flags
            flag = item[2:]
            if flag in {"help", "verbose", "quiet", "overwrite"}:
                dcmd[str(flag)] = True
        elif len(item) == 2 and item[0] == "-":  # -> flags
            if "flags" not in dcmd:
                dcmd["flags"] = ""
            dcmd["flags"] += item[1]
        else:  # unnamed parameter
            module = parse_interface(cmd[0])
            dcmd[module.define_first()] = item

    return (cmd[0], dcmd)


def cmdstring_to_tuple(cmd):
    """Convert command string to tuple for run_command() and others

    :param str cmd: command to be converted

    :return: command as tuple
    """
    return cmdlist_to_tuple(split(cmd))


def cmd_to_python_args(cmd):
    """Format parameters for Python calls, handling illegal keywords.

    :param cmd: list of command arguments (e.g. ['v.distance', 'from=map1', 'to=map2'])
    :return: string of formatted Python arguments ending with a closing parenthesis ')'
    """
    flags = ""
    python_params = []
    # Dictionary for keys that Python can't handle as direct arguments
    illegal_keys = {}

    for item in cmd[1:]:
        if item.startswith("--"):
            val = item.lstrip("-")
            if val in {"overwrite", "o"}:
                python_params.append("overwrite=True")
            elif val == "verbose":
                python_params.append("verbose=True")
            elif val == "quiet":
                python_params.append("quiet=True")
            else:
                python_params.append(f"{val}=True")
        elif item.startswith("-"):
            flags += item.lstrip("-")
        elif "=" in item:
            k, v = item.split("=", 1)
            # If key is a keyword (from, in) or contains dots/dashes,
            # put it into the 'illegal' dictionary
            if keyword.iskeyword(k) or not k.isidentifier():
                illegal_keys[k] = v
            else:
                python_params.append(f"{k}={v!r}")

    # Build the command string
    args = []

    if flags:
        args.append(f"flags='{flags}'")

    args.extend(python_params)

    if illegal_keys:
        # Safe unpacking: **{'from': 'val', 'to': 'val'}
        args.append(f"**{illegal_keys!r}")

    return ", ".join(args) + ")"


def cmd_to_dict(cmd):
    """Extract a dictionary of parameters from the cmd list.

    :param cmd: list of command arguments
    :return: dictionary of parameters and flags
    """
    flags = ""
    python_params = []

    for item in cmd[1:]:
        if item.startswith("--"):
            val = item.lstrip("-")
            if val in {"overwrite", "o"}:
                python_params.append("overwrite=True")
            elif val == "verbose":
                python_params.append("verbose=True")
            elif val == "quiet":
                python_params.append("quiet=True")
            else:
                python_params.append(f"{val}=True")
        elif item.startswith("-"):
            flags += item.lstrip("-")
        elif "=" in item:
            k, v = item.split("=", 1)
            python_params.append(f"{k}={v}")

    params = {"flags": flags}
    for item in python_params:
        if "=" in item:
            k, v = item.split("=", 1)
            params[k] = v
    return params
