import ast
import logging
from typing import List

from prisma.enums import DevelopmentPhase, FunctionState
from prisma.models import Function
from prisma.types import (
    FunctionCreateInput,
    FunctionCreateWithoutRelationsInput,
    FunctionUpdateInput,
    PackageCreateWithoutRelationsInput,
)

from codex.common.ai_block import (
    AIBlock,
    Identifiers,
    ValidatedResponse,
    ValidationError,
)
from codex.develop.model import FunctionDef, GeneratedFunctionResponse, Package

logger = logging.getLogger(__name__)


def parse_requirements(requirements_str: str) -> List[Package]:
    """
    Parses a string of requirements and creates a list of Package objects.

    Args:
    requirements_str (str): A string containing package requirements.

    Returns:
    List[Package]: A list of Package objects.
    """
    logger.debug("🔍 Parsing requirements...")
    packages = []
    version_specifiers = ["==", ">=", "<=", ">", "<", "~=", "!="]
    if requirements_str == "":
        return packages
    for line in requirements_str.splitlines():
        if line:
            # Remove comments and whitespace
            line = line.split("#")[0].strip()
            if not line:
                continue

            package_name, version, specifier = line, None, None

            # Try to split by each version specifier
            for spec in version_specifiers:
                if spec in line:
                    parts = line.split(spec)
                    package_name = parts[0].strip()
                    version = parts[1].strip() if len(parts) > 1 else None
                    specifier = spec
                    break

            package = Package(
                package_name=package_name, version=version, specifier=specifier
            )
            packages.append(package)

    return packages


class FunctionVisitor(ast.NodeVisitor):
    def __init__(self):
        self.functions = {}
        self.imports = []
        self.pydantic_classes = []

    def visit_Import(self, node):
        for alias in node.names:
            import_line = f"import {alias.name}"
            if alias.asname:
                import_line += f" as {alias.asname}"
            self.imports.append(import_line)
        self.generic_visit(node)

    def visit_ImportFrom(self, node):
        for alias in node.names:
            import_line = f"from {node.module} import {alias.name}"
            if alias.asname:
                import_line += f" as {alias.asname}"
            self.imports.append(import_line)
        self.generic_visit(node)

    # TODO(AGPT-425):
    #  - Add visit_ClassDef and parse input output complex types
    #  - Exclude function inside the class and 'unexpected' nested functions.

    def visit_FunctionDef(self, node: ast.FunctionDef) -> None:
        args = []
        for arg in node.args.args:
            arg_type = ast.unparse(arg.annotation) if arg.annotation else "Unknown"
            args.append(arg_type)
        args_str = ", ".join(args)
        return_type = ast.unparse(node.returns) if node.returns else "Unknown"

        # Extract doc_string & function body
        pass_block = ast.parse("pass").body[0]
        if (
            node.body
            and isinstance(node.body[0], ast.Expr)
            and isinstance(node.body[0].value, (ast.Str, ast.Constant))
        ):
            doc_string_body = [node.body[0], pass_block]
            code_body = node.body[1:]
        else:
            doc_string_body = [pass_block]
            code_body = node.body

        # Construct function template
        original_body = node.body.copy()
        node.body = doc_string_body
        function_template = ast.unparse(node)
        node.body = original_body

        # Function is not implemented if it has pass_block as its body
        is_implemented = len(code_body) > 1 or ast.unparse(code_body[0]) != ast.unparse(
            pass_block
        )

        self.functions[node.name] = FunctionDef(
            name=node.name,
            args=args_str,
            return_type=return_type,
            is_implemented=is_implemented,
            function_template=function_template,
            function_code=ast.unparse(node),
        )
        self.generic_visit(node)

    def visit_ClassDef(self, node: ast.ClassDef) -> None:
        """
        Visits a ClassDef node in the AST and checks if it is a Pydantic class.
        If it is a Pydantic class, adds its name to the list of Pydantic classes.
        """
        for base in node.bases:
            base_id = getattr(base, "id", None)
            # This will only work for direct children of BaseModel
            is_pydantic = (isinstance(base, ast.Name) and base.id == "BaseModel") or (
                isinstance(base, ast.Attribute) and base.attr == "BaseModel"
            )
            if is_pydantic:
                self.pydantic_classes.append(node.name)

        self.generic_visit(node)


class DevelopAIBlock(AIBlock):
    developement_phase: DevelopmentPhase = DevelopmentPhase.DEVELOPMENT
    prompt_template_name = "develop"
    model = "gpt-4-0125-preview"
    langauge = "python"

    def validate(
        self, invoke_params: dict, response: ValidatedResponse
    ) -> ValidatedResponse:
        try:
            text = response.response

            requirment_blocks = text.split("```requirements")
            requirment_blocks.pop(0)
            if len(requirment_blocks) != 1:
                packages = []
            else:
                packages: List[Package] = parse_requirements(
                    requirment_blocks[0].split("```")[0]
                )

            code_blocks = text.split("```python")
            code_blocks.pop(0)
            if len(code_blocks) != 1:
                raise ValidationError(
                    f"There are {len(code_blocks)} code blocks in the response. "
                    + "There should be exactly 1"
                )
            code = code_blocks[0].split("```")[0]

            try:
                tree = ast.parse(code)
                visitor = FunctionVisitor()
                visitor.visit(tree)
            except Exception as e:
                # Important: ValidationErrors are used in the retry prompt
                raise ValidationError(f"Error parsing code: {e}")

            func_name = invoke_params["function_name"]
            if func_name not in visitor.functions:
                # Important: ValidationErrors are used in the retry prompt
                raise ValidationError(f"Function {func_name} not found in code")

            requested_func: FunctionDef = visitor.functions[
                invoke_params["function_name"]
            ]

            if not requested_func.is_implemented:
                # Important: ValidationErrors are used in the retry prompt
                raise ValidationError(
                    "Main Function body is empty, it should contain"
                    + " the implementation of this function!"
                )

            functions = visitor.functions.copy()
            del functions[invoke_params["function_name"]]

            response.response = GeneratedFunctionResponse(
                function_id=invoke_params["function_id"]
                if "function_id" in invoke_params
                else None,
                function_name=invoke_params["function_name"],
                api_route_spec=invoke_params["api_route"],
                rawCode=code,
                packages=packages,
                imports=visitor.imports,
                template=requested_func.function_template,
                functionCode=requested_func.function_code,
                functions=functions,
            )
            return response
        except Exception as e:
            # Important: ValidationErrors are used in the retry prompt
            raise ValidationError(f"Error validating response: {e}")

    async def create_item(
        self, ids: Identifiers, validated_response: ValidatedResponse
    ):
        """This is just a temporary that doesnt have a database model"""
        generated_response: GeneratedFunctionResponse = validated_response.response
        if generated_response.function_id:
            # Detect if the function already exists and update it
            return await self.update_item(ids, validated_response)

        try:
            generated_response: GeneratedFunctionResponse = validated_response.response
            function_defs: list[FunctionCreateWithoutRelationsInput] = []
            if generated_response.functions:
                for key, value in generated_response.functions.items():
                    model = FunctionCreateWithoutRelationsInput(
                        functionName=value.name,
                        template=value.function_template,
                        apiRouteSpecId=generated_response.api_route_spec.id,
                        state=FunctionState.WRITTEN
                        if value.is_implemented
                        else FunctionState.DEFINITION,
                        rawCode=value.function_code,
                        functionCode=value.function_code,
                    )

                    function_defs.append(model)

            logger.info(f"Child Functions Detected: {len(function_defs)}")

            create_input = FunctionCreateInput(
                functionName=generated_response.function_name,
                template=generated_response.template,
                state=FunctionState.WRITTEN,
                Packages={
                    "create": [
                        PackageCreateWithoutRelationsInput(
                            packageName=p.package_name,
                            version=p.version if p.version else "",
                            specifier=p.specifier if p.specifier else "",
                        )
                        for p in generated_response.packages
                    ]
                },
                rawCode=generated_response.rawCode,
                importStatements=generated_response.imports,
                functionCode=generated_response.functionCode,
                ChildFunction={"create": function_defs},
                ApiRouteSpec={"connect": {"id": generated_response.api_route_spec.id}},
            )
            if generated_response.api_route_spec.DatabaseSchema:
                create_input["DatabaseSchema"] = {
                    "connect": {
                        "id": generated_response.api_route_spec.DatabaseSchema.id
                    }
                }

            # Child Functions Must be created without relations
            # Here we add the relations after the function is created
            func = await Function.prisma().create(data=create_input)
            if func.ChildFunction:
                for function_def in func.ChildFunction:
                    await Function.prisma().update(
                        where={"id": function_def.id},
                        data={
                            "ApiRouteSpec": {
                                "connect": {"id": generated_response.api_route_spec.id}
                            }
                        },
                    )
            # We need to reload from the database the child functions so they
            # have the api route spec attached
            func = await Function.prisma().find_unique_or_raise(
                where={"id": func.id},
                include={
                    "ParentFunction": True,
                    "ChildFunction": {"include": {"ApiRouteSpec": True}},
                },
            )
            num_child_functions = len(func.ChildFunction) if func.ChildFunction else 0
            logger.info(
                f"✅ Created Function. - {func.id} Child Functions: "
                f"{len(function_defs)}/{num_child_functions}"
            )
            return func
        except Exception as e:
            logger.info(f"Error saving Function: {e}")

    async def update_item(  # type: ignore
        self, ids: Identifiers, validated_response: ValidatedResponse
    ) -> Function:  # type: ignore
        """
        Update an item in the database with the given identifiers
        and validated response.

        Args:
            ids (Identifiers): The identifiers of the item to be updated.
            validated_response (ValidatedResponse): The validated response
                                                containing the updated data.

        Returns:
            func: The updated item
        """
        generated_response: GeneratedFunctionResponse = validated_response.response
        function_defs: list[FunctionCreateWithoutRelationsInput] = []
        if generated_response.functions:
            for key, value in generated_response.functions.items():
                model = FunctionCreateWithoutRelationsInput(
                    functionName=value.name,
                    template=value.function_template,
                    apiRouteSpecId=generated_response.api_route_spec.id,
                    state=FunctionState.DEFINITION,
                )

                function_defs.append(model)

        update_obj = FunctionUpdateInput(
            functionName=generated_response.function_name,
            template=generated_response.template,
            state=FunctionState.WRITTEN,
            Packages={
                "create": [
                    PackageCreateWithoutRelationsInput(
                        packageName=p.package_name,
                        version=p.version if p.version else "",
                        specifier=p.specifier if p.specifier else "",
                    )
                    for p in generated_response.packages
                ]
            },
            rawCode=generated_response.rawCode,
            importStatements=generated_response.imports,
            functionCode=generated_response.functionCode,
            ChildFunction={"create": function_defs},
            ApiRouteSpec={"connect": {"id": generated_response.api_route_spec.id}},
        )

        if not generated_response.function_id:
            raise AssertionError("Function ID is required to update")

        func: Function | None = await Function.prisma().update(
            where={"id": generated_response.function_id}, data=update_obj
        )
        if not func:
            raise AssertionError(
                f"Function with id {generated_response.function_id} not found"
            )

        # Child Functions Must be created without relations
        # Here we add the relations after the function is created
        if func.ChildFunction:
            for function_def in func.ChildFunction:
                await Function.prisma().update(
                    where={"id": function_def.id},
                    data={
                        "ApiRouteSpec": {
                            "connect": {"id": generated_response.api_route_spec.id}
                        }
                    },
                )
        # We need to reload from the database the child functions so they
        # have the api route spec attached
        func = await Function.prisma().find_unique_or_raise(
            where={"id": func.id},
            include={
                "ParentFunction": True,
                "ChildFunction": {"include": {"ApiRouteSpec": True}},
            },
        )

        logger.info(f"✅ Updated Function: {func.functionName} - {func.id}")

        return func