from core_domain import InitialNodeContract, NodeRunStatus, WorkflowRunStatus

from app.db.models import NodeRun, WorkflowRun
from app.domain.repositories import NodeRunRepository, WorkflowRunRepository
from app.infrastructure.planner import derive_initial_node, derive_successor_nodes
from app.infrastructure.workflow_client import WorkflowServiceClient
from app.schemas.run import NodeRunStatusUpdateRequest, RunCreateRequest, WorkflowRunStatusUpdateRequest


class RuntimeApplicationService:
    def __init__(
        self,
        workflow_run_repository: WorkflowRunRepository,
        node_run_repository: NodeRunRepository,
        workflow_client: WorkflowServiceClient | None = None,
    ) -> None:
        self.workflow_run_repository = workflow_run_repository
        self.node_run_repository = node_run_repository
        self.workflow_client = workflow_client

    def create_run(self, payload: RunCreateRequest) -> tuple[WorkflowRun, NodeRun | None]:
        initial_node = payload.initial_node or self._plan_initial_node(payload)
        workflow_run = self.workflow_run_repository.create(
            tenant_id=payload.tenant_id,
            app_id=payload.app_id,
            app_version_id=payload.app_version_id,
            workflow_id=payload.workflow_id,
            workflow_version_id=payload.workflow_version_id,
            session_id=payload.session_id,
            parent_run_id=payload.parent_run_id,
            root_run_id=payload.root_run_id,
            run_type=payload.run_type,
            trigger_type=payload.trigger_type,
            priority=payload.priority,
        )

        node_run = None
        if initial_node is not None:
            self.workflow_run_repository.update_node_count(
                run_id=workflow_run.id,
                current_node_count=1,
            )
            node_run = self.node_run_repository.create(
                tenant_id=payload.tenant_id,
                run_id=workflow_run.id,
                node_id=initial_node.node_id,
                node_type=initial_node.node_type,
                status=initial_node.status,
            )

        return workflow_run, node_run

    def list_runs(self, tenant_id: str, session_id: str | None = None) -> list[WorkflowRun]:
        return self.workflow_run_repository.list_by_scope(tenant_id=tenant_id, session_id=session_id)

    def list_node_runs(self, tenant_id: str, run_id: str) -> list[NodeRun]:
        return self.node_run_repository.list_by_run(tenant_id=tenant_id, run_id=run_id)

    def update_run_status(
        self,
        run_id: str,
        payload: WorkflowRunStatusUpdateRequest,
    ) -> WorkflowRun | None:
        return self.workflow_run_repository.update_status(
            run_id=run_id,
            status=payload.status,
            error_code=payload.error_code,
            error_message=payload.error_message,
        )

    def update_node_run_status(
        self,
        node_run_id: str,
        payload: NodeRunStatusUpdateRequest,
    ) -> NodeRun | None:
        node_run = self.node_run_repository.update_status(
            node_run_id=node_run_id,
            status=payload.status,
            worker_key=payload.worker_key,
            error_code=payload.error_code,
            error_message=payload.error_message,
        )
        if node_run is None:
            return None

        if payload.status == "completed":
            self._schedule_successor_nodes(node_run)

        self._sync_workflow_run_status_from_nodes(
            tenant_id=node_run.tenant_id,
            run_id=node_run.run_id,
        )
        return node_run

    def _plan_initial_node(self, payload: RunCreateRequest) -> InitialNodeContract | None:
        if self.workflow_client is None:
            return None
        workflow_version = self.workflow_client.get_workflow_version(
            tenant_id=payload.tenant_id,
            workflow_version_id=payload.workflow_version_id,
        )
        return derive_initial_node(workflow_version)

    def _schedule_successor_nodes(self, node_run: NodeRun) -> None:
        if self.workflow_client is None:
            return

        workflow_run = self.workflow_run_repository.get_by_id(node_run.run_id)
        if workflow_run is None:
            return

        workflow_version = self.workflow_client.get_workflow_version(
            tenant_id=node_run.tenant_id,
            workflow_version_id=workflow_run.workflow_version_id,
        )
        successor_nodes = derive_successor_nodes(workflow_version, node_run.node_id)
        if not successor_nodes:
            return

        existing_nodes = self.node_run_repository.list_by_run_and_node_ids(
            tenant_id=node_run.tenant_id,
            run_id=node_run.run_id,
            node_ids=[item.node_id for item in successor_nodes],
        )
        existing_node_ids = {item.node_id for item in existing_nodes}

        for successor in successor_nodes:
            if successor.node_id in existing_node_ids:
                continue
            self.node_run_repository.create(
                tenant_id=node_run.tenant_id,
                run_id=node_run.run_id,
                node_id=successor.node_id,
                node_type=successor.node_type,
                status=successor.status,
            )

    def _sync_workflow_run_status_from_nodes(self, *, tenant_id: str, run_id: str) -> None:
        node_runs = self.node_run_repository.list_by_run(tenant_id=tenant_id, run_id=run_id)
        if not node_runs:
            return

        self.workflow_run_repository.update_node_count(
            run_id=run_id,
            current_node_count=len(node_runs),
        )

        next_status, error_code, error_message = self._derive_run_status(node_runs)
        self.workflow_run_repository.update_status(
            run_id=run_id,
            status=next_status,
            error_code=error_code,
            error_message=error_message,
        )

    def _derive_run_status(
        self,
        node_runs: list[NodeRun],
    ) -> tuple[WorkflowRunStatus, str | None, str | None]:
        statuses = {node_run.status for node_run in node_runs}

        if "failed" in statuses:
            failed_node = next((item for item in node_runs if item.status == "failed"), None)
            error_code = failed_node.error_code if failed_node is not None else None
            error_message = failed_node.error_message if failed_node is not None else None
            return "failed", error_code, error_message

        if "running" in statuses:
            return "running", None, None

        terminal_statuses: set[NodeRunStatus] = {"completed", "skipped"}
        if statuses and statuses.issubset(terminal_statuses):
            return "completed", None, None

        return "running", None, None