"""
Created on Tue Apr  2 18:31:47 2013

@author: pietro
"""
from __future__ import (
    nested_scopes,
    generators,
    division,
    absolute_import,
    with_statement,
    print_function,
    unicode_literals,
)
import re

from grass.pygrass.modules.interface.docstring import docstring_property
from grass.pygrass.modules.interface.read import GETTYPE, element2dict, DOC


def _check_value(param, value):
    """Function to check the correctness of a value and
    return the checked value and the original.
    """
    must_val = "The Parameter <%s>, must be one of the following values: %r"
    req = "The Parameter <%s>, require: %s, get: %s instead: %r\n%s"
    string = (type(b""), type(""))

    def raiseexcpet(exc, param, ptype, value):
        """Function to modifa the error message"""
        msg = req % (param.name, param.typedesc, ptype, value, str(exc))
        if isinstance(exc, ValueError):
            raise ValueError(msg)
        elif isinstance(exc, TypeError):
            raise TypeError(msg)
        else:
            exc.message = msg
            raise exc

    def check_string(value):
        """Function to check that a string parameter is already a string"""
        if param.type in string:
            if type(value) in (int, float):
                value = str(value)
            if type(value) not in string:
                msg = (
                    "The Parameter <%s> require a string," " %s instead is provided: %r"
                )
                raise ValueError(msg % (param.name, type(value), value))
        return value

    # return None if None
    if value is None:
        return param.default, param.default

    # find errors with multiple parameters
    if isinstance(value, (list, tuple)):
        if param.keydescvalues:
            return (
                (
                    [
                        value,
                    ],
                    value,
                )
                if isinstance(value, tuple)
                else (value, value)
            )
        if param.multiple:
            # everything looks fine, so check each value
            try:
                return [param.type(check_string(val)) for val in value], value
            except Exception as exc:
                raiseexcpet(exc, param, param.type, value)
        else:
            msg = "The Parameter <%s> does not accept multiple inputs"
            raise TypeError(msg % param.name)

    if param.keydescvalues:
        msg = "The Parameter <%s> require multiple inputs in the form: %s"
        raise TypeError(msg % (param.name, param.keydescvalues))

    if param.typedesc == "all":
        return value, value

    # check string before trying to convert value to the correct type
    check_string(value)
    # the value is a scalar
    try:
        newvalue = param.type(value)
    except Exception as exc:
        raiseexcpet(exc, param, type(value), value)

    # check values
    if hasattr(param, "values"):
        if param.type in (float, int):
            # check for value in range
            if (param.min is not None and newvalue < param.min) or (
                param.max is not None and newvalue > param.max
            ):
                if param.min is None:
                    err_str = (
                        f"The Parameter <{param.name}> must be lower than "
                        f"{param.max}, {newvalue} is outside."
                    )
                elif param.max is None:
                    err_str = (
                        f"The Parameter <{param.name}> must be higher than "
                        f"{param.min}, {newvalue} is out of range."
                    )
                else:
                    err_str = (
                        f"The Parameter <{param.name}> must be between: "
                        f"{param.min}<=value<={param.max}, {newvalue} is outside."
                    )
                raise ValueError(err_str)
        # check if value is in the list of valid values
        if param.values is not None and newvalue not in param.values:
            raise ValueError(must_val % (param.name, param.values))
    return (
        (
            [
                newvalue,
            ]
            if (param.multiple or param.keydescvalues)
            else newvalue
        ),
        value,
    )


# TODO add documentation
class Parameter(object):
    """The Parameter object store all information about a parameter of a
    GRASS GIS module. ::

        >>> param = Parameter(diz=dict(name='int_number', required='yes',
        ...                            multiple='no', type='integer',
        ...                            values=[2, 4, 6, 8]))
        >>> param.value = 2
        >>> param.value
        2
        >>> param.value = 3
        Traceback (most recent call last):
           ...
        ValueError: The Parameter <int_number>, must be one of the following values: [2, 4, 6, 8]

    ...
    """

    def __init__(self, xparameter=None, diz=None):
        self._value = None
        self._rawvalue = None
        self.min = None
        self.max = None
        diz = element2dict(xparameter) if xparameter is not None else diz
        if diz is None:
            raise TypeError("Xparameter or diz are required")
        self.name = diz["name"]
        self.required = True if diz["required"] == "yes" else False
        self.multiple = True if diz["multiple"] == "yes" else False
        # check the type
        if diz["type"] in GETTYPE:
            self.type = GETTYPE[diz["type"]]
            self.typedesc = diz["type"]
        else:
            raise TypeError("New type: %s, ignored" % diz["type"])

        self.description = diz.get("description", None)
        self.keydesc, self.keydescvalues = diz.get("keydesc", (None, None))

        #
        # values
        #
        if "values" in diz:
            try:
                # Check for integer ranges: "3-30" or float ranges: "0.0-1.0"
                isrange = re.match(
                    "(?P<min>-*\d+.*\d*)*-(?P<max>\d+.*\d*)*", diz["values"][0]
                )
                if isrange:
                    mn, mx = isrange.groups()
                    self.min = None if mn is None else float(mn)
                    self.max = None if mx is None else float(mx)
                    self.values = None
                    self.isrange = diz["values"][0]
                # No range was found
                else:
                    self.values = [self.type(i) for i in diz["values"]]
                    self.isrange = False
            except TypeError:
                self.values = [self.type(i) for i in diz["values"]]
                self.isrange = False

        #
        # default
        #
        if "default" in diz and diz["default"]:
            if self.multiple or self.keydescvalues:
                self.default = [self.type(v) for v in diz["default"].split(",")]
            else:
                self.default = self.type(diz["default"])
        else:
            self.default = None
        self._value, self._rawvalue = self.default, self.default
        self.guisection = diz.get("guisection", None)

        #
        # gisprompt
        #
        if "gisprompt" in diz and diz["gisprompt"]:
            self.typedesc = diz["gisprompt"].get("prompt", "")
            self.input = False if diz["gisprompt"]["age"] == "new" else True
        else:
            self.input = True

    def _get_value(self):
        return self._value

    def _set_value(self, value):
        self._value, self._rawvalue = _check_value(self, value)

    # here the property function is used to transform value in an attribute
    # in this case we define which function must be use to get/set the value
    value = property(
        fget=_get_value,
        fset=_set_value,
        doc="Parameter value transformed and validated.",
    )

    @property
    def rawvalue(self):
        """Parameter value as insert by user without transformation"""
        return self._rawvalue

    def get_bash(self):
        """Return the BASH representation of the parameter. ::

            >>> param = Parameter(diz=dict(name='int_number', required='yes',
            ...                            multiple='no', type='integer',
            ...                            values=[2, 4, 6, 8], default=8))
            >>> param.get_bash()
            'int_number=8'

        ..
        """
        sep = ","
        if isinstance(self.rawvalue, (list, tuple)):
            value = sep.join(
                [
                    sep.join([str(v) for v in val])
                    if isinstance(val, tuple)
                    else str(val)
                    for val in self.rawvalue
                ]
            )
        else:
            value = str(self.rawvalue)
        return "%s=%s" % (self.name, value)

    def get_python(self):
        """Return a string with the Python representation of the parameter. ::

            >>> param = Parameter(diz=dict(name='int_number', required='yes',
            ...                            multiple='no', type='integer',
            ...                            values=[2, 4, 6, 8], default=8))
            >>> param.get_python()
            'int_number=8'

        ..
        """
        if self.value is None:
            return ""
        return """%s=%r""" % (self.name, self.value)

    def __str__(self):
        """Return the BASH representation of the GRASS module parameter."""
        return self.get_bash()

    def __repr__(self):
        """Return the python representation of the GRASS module parameter."""
        str_repr = "Parameter <%s> (required:%s, type:%s, multiple:%s)"
        mtype = ("raster", "vector")  # map type
        return str_repr % (
            self.name,
            "yes" if self.required else "no",
            self.type if self.type in mtype else self.typedesc,
            "yes" if self.multiple else "no",
        )

    @docstring_property(__doc__)
    def __doc__(self):
        """Return the docstring of the parameter

        {name}: {default}{required}{multi}{ptype}
            {description}{values}"",

        ::

            >>> param = Parameter(diz=dict(name='int_number',
            ...                            description="Set an number",
            ...                            required='yes',
            ...                            multiple='no', type='integer',
            ...                            values=[2, 4, 6, 8], default=8))
            >>> print(param.__doc__)
            int_number: 8, required, integer
                Set an number
                Values: 2, 4, 6, 8
        ..
        """
        if hasattr(self, "values"):
            if self.isrange:
                vals = self.isrange
            else:
                vals = ", ".join([repr(val) for val in self.values])
        else:
            vals = False
        if self.keydescvalues:
            keydescvals = "\n    (%s)" % ", ".join(self.keydescvalues)
        return DOC["param"].format(
            name=self.name,
            default=repr(self.default) + ", " if self.default else "",
            required="required, " if self.required else "optional, ",
            multi="multi" if self.multiple else "",
            ptype=self.typedesc,
            description=self.description,
            values="\n    Values: {0}".format(vals) if vals else "",
            keydescvalues=keydescvals if self.keydescvalues else "",
        )
