from __future__ import annotations

import time
from collections.abc import Mapping
from dataclasses import dataclass

import pytest

from dify_graph.entities import GraphInitParams
from dify_graph.enums import ErrorStrategy, NodeExecutionType, NodeType
from dify_graph.graph import Graph
from dify_graph.graph.validation import GraphValidationError
from dify_graph.nodes.base.entities import BaseNodeData
from dify_graph.nodes.base.node import Node
from dify_graph.runtime import GraphRuntimeState, VariablePool
from dify_graph.system_variable import SystemVariable
from tests.workflow_test_utils import build_test_graph_init_params


class _TestNodeData(BaseNodeData):
    type: NodeType | str | None = None
    execution_type: NodeExecutionType | str | None = None


class _TestNode(Node[_TestNodeData]):
    node_type = NodeType.ANSWER
    execution_type = NodeExecutionType.EXECUTABLE

    @classmethod
    def version(cls) -> str:
        return "1"

    def __init__(
        self,
        *,
        id: str,
        config: Mapping[str, object],
        graph_init_params: GraphInitParams,
        graph_runtime_state: GraphRuntimeState,
    ) -> None:
        super().__init__(
            id=id,
            config=config,
            graph_init_params=graph_init_params,
            graph_runtime_state=graph_runtime_state,
        )

        node_type_value = self.data.get("type")
        if isinstance(node_type_value, NodeType):
            self.node_type = node_type_value
        elif isinstance(node_type_value, str):
            try:
                self.node_type = NodeType(node_type_value)
            except ValueError:
                pass

    def _run(self):
        raise NotImplementedError

    def post_init(self) -> None:
        super().post_init()
        self._maybe_override_execution_type()
        self.data = dict(self.node_data.model_dump())

    def _maybe_override_execution_type(self) -> None:
        execution_type_value = self.node_data.execution_type
        if execution_type_value is None:
            return
        if isinstance(execution_type_value, NodeExecutionType):
            self.execution_type = execution_type_value
        else:
            self.execution_type = NodeExecutionType(execution_type_value)


@dataclass(slots=True)
class _SimpleNodeFactory:
    graph_init_params: GraphInitParams
    graph_runtime_state: GraphRuntimeState

    def create_node(self, node_config: Mapping[str, object]) -> _TestNode:
        node_id = str(node_config["id"])
        node = _TestNode(
            id=node_id,
            config=node_config,
            graph_init_params=self.graph_init_params,
            graph_runtime_state=self.graph_runtime_state,
        )
        return node


@pytest.fixture
def graph_init_dependencies() -> tuple[_SimpleNodeFactory, dict[str, object]]:
    graph_config: dict[str, object] = {"edges": [], "nodes": []}
    init_params = build_test_graph_init_params(
        workflow_id="workflow",
        graph_config=graph_config,
        tenant_id="tenant",
        app_id="app",
        user_id="user",
        user_from="account",
        invoke_from="service-api",
        call_depth=0,
    )
    variable_pool = VariablePool(system_variables=SystemVariable(user_id="user", files=[]), user_inputs={})
    runtime_state = GraphRuntimeState(variable_pool=variable_pool, start_at=time.perf_counter())
    factory = _SimpleNodeFactory(graph_init_params=init_params, graph_runtime_state=runtime_state)
    return factory, graph_config


def test_graph_initialization_runs_default_validators(
    graph_init_dependencies: tuple[_SimpleNodeFactory, dict[str, object]],
):
    node_factory, graph_config = graph_init_dependencies
    graph_config["nodes"] = [
        {"id": "start", "data": {"type": NodeType.START, "title": "Start", "execution_type": NodeExecutionType.ROOT}},
        {"id": "answer", "data": {"type": NodeType.ANSWER, "title": "Answer"}},
    ]
    graph_config["edges"] = [
        {"source": "start", "target": "answer", "sourceHandle": "success"},
    ]

    graph = Graph.init(graph_config=graph_config, node_factory=node_factory)

    assert graph.root_node.id == "start"
    assert "answer" in graph.nodes


def test_graph_validation_fails_for_unknown_edge_targets(
    graph_init_dependencies: tuple[_SimpleNodeFactory, dict[str, object]],
) -> None:
    node_factory, graph_config = graph_init_dependencies
    graph_config["nodes"] = [
        {"id": "start", "data": {"type": NodeType.START, "title": "Start", "execution_type": NodeExecutionType.ROOT}},
    ]
    graph_config["edges"] = [
        {"source": "start", "target": "missing", "sourceHandle": "success"},
    ]

    with pytest.raises(GraphValidationError) as exc:
        Graph.init(graph_config=graph_config, node_factory=node_factory)

    assert any(issue.code == "MISSING_NODE" for issue in exc.value.issues)


def test_graph_promotes_fail_branch_nodes_to_branch_execution_type(
    graph_init_dependencies: tuple[_SimpleNodeFactory, dict[str, object]],
) -> None:
    node_factory, graph_config = graph_init_dependencies
    graph_config["nodes"] = [
        {"id": "start", "data": {"type": NodeType.START, "title": "Start", "execution_type": NodeExecutionType.ROOT}},
        {
            "id": "branch",
            "data": {
                "type": NodeType.IF_ELSE,
                "title": "Branch",
                "error_strategy": ErrorStrategy.FAIL_BRANCH,
            },
        },
    ]
    graph_config["edges"] = [
        {"source": "start", "target": "branch", "sourceHandle": "success"},
    ]

    graph = Graph.init(graph_config=graph_config, node_factory=node_factory)

    assert graph.nodes["branch"].execution_type == NodeExecutionType.BRANCH


def test_graph_validation_blocks_start_and_trigger_coexistence(
    graph_init_dependencies: tuple[_SimpleNodeFactory, dict[str, object]],
) -> None:
    node_factory, graph_config = graph_init_dependencies
    graph_config["nodes"] = [
        {"id": "start", "data": {"type": NodeType.START, "title": "Start", "execution_type": NodeExecutionType.ROOT}},
        {
            "id": "trigger",
            "data": {"type": NodeType.TRIGGER_WEBHOOK, "title": "Webhook", "execution_type": NodeExecutionType.ROOT},
        },
    ]
    graph_config["edges"] = []

    with pytest.raises(GraphValidationError) as exc_info:
        Graph.init(graph_config=graph_config, node_factory=node_factory)

    assert any(issue.code == "TRIGGER_START_NODE_CONFLICT" for issue in exc_info.value.issues)
