# -*- coding: utf-8 -*-
import typing

#  Copyright (c) 2021, University of Luxembourg / DHARPA project
#  Copyright (c) 2021, Markus Binsteiner
#
#  Mozilla Public License, version 2.0 (see LICENSE or https://www.mozilla.org/en-US/MPL/2.0/)
import uuid
from typing import Any, Dict, List, Union

from pydantic import BaseModel, ConfigDict, Field, PrivateAttr, model_validator

from kiara.defaults import PIPELINE_PARENT_MARKER
from kiara.models.values.value_schema import ValueSchema
from kiara.utils import camel_case_to_snake_case

if typing.TYPE_CHECKING:
    pass


def generate_step_alias(step_id: str, value_name) -> str:
    return f"{step_id}.{value_name}"


class StepValueAddress(BaseModel):
    """Small model to describe the address of a value of a step, within a Pipeline/PipelineStructure."""

    model_config = ConfigDict(extra="forbid")

    step_id: str = Field(description="The id of a step within a pipeline.")
    value_name: str = Field(
        description="The name of the value (output name or pipeline input name)."
    )
    sub_value: Union[Dict[str, Any], None] = Field(
        default=None,
        description="A reference to a subitem of a value (e.g. column, list item)",
    )

    @property
    def alias(self):
        """An alias string for this address (in the form ``[step_id].[value_name]``)."""
        return generate_step_alias(self.step_id, self.value_name)

    def __eq__(self, other):

        if not isinstance(other, StepValueAddress):
            return False

        return (self.step_id, self.value_name, self.sub_value) == (
            other.step_id,
            other.value_name,
            other.sub_value,
        )

    def __hash__(self):

        return hash((self.step_id, self.value_name, self.sub_value))

    def __repr__(self):

        if self.sub_value:
            sub_value = f" sub_value={self.sub_value}"
        else:
            sub_value = ""
        return f"{self.__class__.__name__}(step_id={self.step_id}, value_name={self.value_name}{sub_value})"

    def __str__(self):
        return self.__repr__()


class ValueRef(BaseModel):
    """
    An object that holds information about the location of a value within a pipeline (or other structure).

    Basically, a `ValueRef` helps the containing object where in its structure the value belongs (for example so
    it can update dependent other values). A `ValueRef` object (obviously) does not contain the value itself.

    There are four different ValueRef type that are relevant for pipelines:

    - [kiara.pipeline.values.StepInputRef][]: an input to a step
    - [kiara.pipeline.values.StepOutputRef][]: an output of a step
    - [kiara.pipeline.values.PipelineInputRef][]: an input to a pipeline
    - [kiara.pipeline.values.PipelineOutputRef][]: an output for a pipeline

    Several `ValueRef` objects can target the same value, for example a step output and a connected step input would
    reference the same `Value` (in most cases)..
    """

    model_config = ConfigDict(frozen=False, extra="forbid")

    _id: uuid.UUID = PrivateAttr(default_factory=uuid.uuid4)
    value_name: str
    value_schema: ValueSchema

    def __eq__(self, other):

        if not isinstance(other, self.__class__):
            return False

        return self._id == other._id

    def __hash__(self):
        return hash(self._id)

    def __repr__(self):
        step_id = ""
        if hasattr(self, "step_id"):
            step_id = f" step_id='{self.step_id}'"
        return f"{self.__class__.__name__}(value_name='{self.value_name}' {step_id})"

    def __str__(self):
        name = camel_case_to_snake_case(self.__class__.__name__[0:-5], repl=" ")
        return f"{name}: {self.value_name} ({self.value_schema.type})"


class StepInputRef(ValueRef):
    """
    An input to a step.

    This object can either have a 'connected_outputs' set, or a 'connected_pipeline_input', not both.
    """

    step_id: str = Field(description="The step id.")
    connected_outputs: Union[List[StepValueAddress], None] = Field(
        default=None,
        description="A potential connected list of one or several module outputs.",
    )
    connected_pipeline_input: Union[str, None] = Field(
        default=None, description="A potential pipeline input."
    )
    is_constant: bool = Field(
        description="Whether this input is a constant and can't be changed by the user."
    )

    @model_validator(mode="before")
    @classmethod
    def ensure_single_connected_item(cls, values):

        if values.get("connected_outputs", None) and values.get(
            "connected_pipeline_input"
        ):
            raise ValueError("Multiple connected items, only one allowed.")

        return values

    @property
    def alias(self) -> str:
        return generate_step_alias(self.step_id, self.value_name)

    @property
    def address(self) -> StepValueAddress:
        return StepValueAddress(step_id=self.step_id, value_name=self.value_name)

    def __str__(self):
        name = camel_case_to_snake_case(self.__class__.__name__[0:-5], repl=" ")
        return f"{name}: {self.step_id}.{self.value_name} ({self.value_schema.type})"


class StepOutputRef(ValueRef):
    """An output to a step."""

    model_config = ConfigDict(frozen=False)

    step_id: str = Field(description="The step id.")
    pipeline_output: Union[str, None] = Field(
        description="The connected pipeline output."
    )
    connected_inputs: List[StepValueAddress] = Field(
        description="The step inputs that are connected to this step output",
        default_factory=list,
    )

    @property
    def alias(self) -> str:
        return generate_step_alias(self.step_id, self.value_name)

    @property
    def address(self) -> StepValueAddress:
        return StepValueAddress(step_id=self.step_id, value_name=self.value_name)

    def __str__(self):
        name = camel_case_to_snake_case(self.__class__.__name__[0:-5], repl=" ")
        return f"{name}: {self.step_id}.{self.value_name} ({self.value_schema.type})"


class PipelineInputRef(ValueRef):
    """An input to a pipeline."""

    connected_inputs: List[StepValueAddress] = Field(
        description="The step inputs that are connected to this pipeline input",
        default_factory=list,
    )
    is_constant: bool = Field(
        description="Whether this input is a constant and can't be changed by the user."
    )

    @property
    def alias(self) -> str:
        return generate_step_alias(PIPELINE_PARENT_MARKER, self.value_name)


class PipelineOutputRef(ValueRef):
    """An output to a pipeline."""

    connected_output: StepValueAddress = Field(description="Connected step outputs.")

    @property
    def alias(self) -> str:
        return generate_step_alias(PIPELINE_PARENT_MARKER, self.value_name)


StepInputRef.model_rebuild()
StepOutputRef.model_rebuild()