# -*- coding: utf-8 -*-
import os
from pathlib import Path
from typing import Any, Dict, Iterable, List, Mapping, Union

from pydantic import BaseModel, Field, field_validator

from kiara.exceptions import KiaraProcessingException
from kiara.models.module import KiaraModuleConfig
from kiara.models.values.value import ValueMap
from kiara.modules import KiaraModule, ValueMapSchema


class DataExportResult(BaseModel):

    files: List[str] = Field(description="A list of exported files.")

    @field_validator("files", mode="before")
    @classmethod
    def validate_files(cls, value):

        if isinstance(value, str):
            value = [value]

        # TODO: make sure file exists
        value = [x.as_posix() if isinstance(x, Path) else x for x in value]

        return value


class DataExportModuleConfig(KiaraModuleConfig):

    target_profile: str = Field(
        description="The name of the target profile. Used to distinguish different target formats for the same data type."
    )
    source_type: str = Field(
        description="The type of the source data that is going to be exported."
    )


class DataExportModule(KiaraModule):

    _config_cls = DataExportModuleConfig
    _module_type_name: Union[str, None] = None

    @classmethod
    def retrieve_supported_export_combinations(cls) -> Iterable[Mapping[str, str]]:

        result = []
        for attr in dir(cls):
            if (
                len(attr) <= 16
                or not attr.startswith("export__")
                or "__as__" not in attr
            ):
                continue

            tokens = attr.split("__", maxsplit=4)
            if len(tokens) != 4:
                continue

            source_type = tokens[1]
            target_profile = tokens[3]

            data = {
                "source_type": source_type,
                "target_profile": target_profile,
                "func": attr,
            }
            result.append(data)
        return result

    def create_optional_inputs(
        self, source_type: str, target_profile: str
    ) -> Union[None, Mapping[str, Mapping[str, Any]]]:
        return None

    def create_inputs_schema(
        self,
    ) -> ValueMapSchema:

        source_type = self.get_config_value("source_type")
        target_profile = self.get_config_value("target_profile")

        inputs: Dict[str, Any] = {
            source_type: {
                "type": source_type,
                "doc": f"A value of type '{source_type}'.",
            },
            "base_path": {
                "type": "string",
                "doc": "The directory to export the file(s) to.",
                "optional": True,
            },
            "name": {
                "type": "string",
                "doc": "The (base) name of the exported file(s).",
                "optional": True,
            },
            "export_metadata": {
                "type": "boolean",
                "doc": "Whether to also export the value metadata.",
                "default": False,
            },
        }

        optional = self.create_optional_inputs(
            source_type=source_type, target_profile=target_profile
        )
        if optional:
            for field, field_schema in optional.items():
                field_schema = dict(field_schema)
                if field in inputs.keys():
                    raise Exception(
                        f"Can't create inputs schema for '{self.module_type_name}': duplicate field '{field}'."
                    )
                if field == source_type:
                    raise Exception(
                        f"Can't create inputs schema for '{self.module_type_name}': invalid field name '{field}'."
                    )

                optional = field_schema.get("optional", True)
                if not optional:
                    raise Exception(
                        f"Can't create inputs schema for '{self.module_type_name}': non-optional field '{field}' specified."
                    )
                field_schema["optional"] = True
                inputs[field] = field_schema

        return inputs

    def create_outputs_schema(
        self,
    ) -> ValueMapSchema:

        outputs = {
            "export_details": {
                "type": "dict",
                "doc": "Details about the exported files/folders.",
            }
        }
        return outputs

    def process(self, inputs: ValueMap, outputs: ValueMap) -> None:

        target_profile: str = self.get_config_value("target_profile")
        source_type: str = self.get_config_value("source_type")

        export_metadata = inputs.get_value_data("export_metadata")

        source_obj = inputs.get_value_obj(source_type)
        source = source_obj.data

        func_name = f"export__{source_type}__as__{target_profile}"
        if not hasattr(self, func_name):
            raise Exception(
                f"Can't export '{source_type}' value: missing function '{func_name}' in class '{self.__class__.__name__}'. Please check this modules documentation or source code to determine which source types and profiles are supported."
            )

        base_path = inputs.get_value_data("base_path")
        if base_path is None:
            base_path = os.getcwd()
        name = inputs.get_value_data("name")
        if not name:
            name = str(source_obj.value_id)

        func = getattr(self, func_name)
        # TODO: check signature?

        base_path = os.path.abspath(base_path)
        os.makedirs(base_path, exist_ok=True)
        result = func(value=source, base_path=base_path, name=name)

        if isinstance(result, Mapping):
            result = DataExportResult(**result)
        elif isinstance(result, str):
            result = DataExportResult(files=[result])

        if not isinstance(result, DataExportResult):
            raise KiaraProcessingException(
                f"Can't export value: invalid result type '{type(result)}' from internal method. This is most likely a bug in the '{self.module_type_name}' module code."
            )

        if export_metadata:
            metadata_file = Path(os.path.join(base_path, f"{name}.metadata"))
            value_info = source_obj.create_info()
            value_json = value_info.model_dump_json()
            metadata_file.write_text(value_json)

            result.files.append(metadata_file.as_posix())

        # schema = ValueSchema(type=self.get_target_value_type(), doc="Imported dataset.")

        # value_lineage = ValueLineage.from_module_and_inputs(
        #     module=self, output_name=output_key, inputs=inputs
        # )
        # value: Value = self._kiara.data_registry.register_data(
        #     value_data=result, value_schema=schema, lineage=None
        # )

        outputs.set_value("export_details", result)