"""
Script Flow Management API.
[AC-AISVC-71, AC-AISVC-72, AC-AISVC-73] Script flow CRUD endpoints.
"""

import logging
import uuid
from typing import Any

from fastapi import APIRouter, Depends, Header, HTTPException
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.database import get_session
from app.models.entities import ScriptFlowCreate, ScriptFlowUpdate
from app.services.flow.flow_service import ScriptFlowService

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/admin/script-flows", tags=["Script Flows"])


def get_tenant_id(x_tenant_id: str = Header(..., alias="X-Tenant-Id")) -> str:
    """Extract tenant ID from header."""
    if not x_tenant_id:
        raise HTTPException(status_code=400, detail="X-Tenant-Id header is required")
    return x_tenant_id


@router.get("")
async def list_flows(
    tenant_id: str = Depends(get_tenant_id),
    is_enabled: bool | None = None,
    session: AsyncSession = Depends(get_session),
) -> dict[str, Any]:
    """
    [AC-AISVC-72] List all script flows for a tenant.
    """
    logger.info(f"[AC-AISVC-72] Listing script flows for tenant={tenant_id}, is_enabled={is_enabled}")

    service = ScriptFlowService(session)
    flows = await service.list_flows(tenant_id, is_enabled)

    data = []
    for f in flows:
        linked_rule_count = await service._get_linked_rule_count(tenant_id, f.id)
        data.append({
            "id": str(f.id),
            "name": f.name,
            "description": f.description,
            "step_count": len(f.steps),
            "is_enabled": f.is_enabled,
            "linked_rule_count": linked_rule_count,
            "created_at": f.created_at.isoformat(),
            "updated_at": f.updated_at.isoformat(),
        })

    return {"data": data}


@router.post("", status_code=201)
async def create_flow(
    body: ScriptFlowCreate,
    tenant_id: str = Depends(get_tenant_id),
    session: AsyncSession = Depends(get_session),
) -> dict[str, Any]:
    """
    [AC-AISVC-71] Create a new script flow.
    """
    logger.info(f"[AC-AISVC-71] Creating script flow for tenant={tenant_id}, name={body.name}")

    service = ScriptFlowService(session)
    
    try:
        flow = await service.create_flow(tenant_id, body)
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))

    return {
        "id": str(flow.id),
        "name": flow.name,
        "description": flow.description,
        "step_count": len(flow.steps),
        "is_enabled": flow.is_enabled,
        "created_at": flow.created_at.isoformat(),
        "updated_at": flow.updated_at.isoformat(),
    }


@router.get("/{flow_id}")
async def get_flow_detail(
    flow_id: uuid.UUID,
    tenant_id: str = Depends(get_tenant_id),
    session: AsyncSession = Depends(get_session),
) -> dict[str, Any]:
    """
    [AC-AISVC-73] Get script flow detail with complete step definitions.
    """
    logger.info(f"[AC-AISVC-73] Getting flow detail for tenant={tenant_id}, id={flow_id}")

    service = ScriptFlowService(session)
    detail = await service.get_flow_detail(tenant_id, flow_id)

    if not detail:
        raise HTTPException(status_code=404, detail="Flow not found")

    return detail


@router.put("/{flow_id}")
async def update_flow(
    flow_id: uuid.UUID,
    body: ScriptFlowUpdate,
    tenant_id: str = Depends(get_tenant_id),
    session: AsyncSession = Depends(get_session),
) -> dict[str, Any]:
    """
    [AC-AISVC-73] Update script flow definition.
    """
    logger.info(f"[AC-AISVC-73] Updating flow for tenant={tenant_id}, id={flow_id}")

    service = ScriptFlowService(session)
    
    try:
        flow = await service.update_flow(tenant_id, flow_id, body)
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))

    if not flow:
        raise HTTPException(status_code=404, detail="Flow not found")

    return {
        "id": str(flow.id),
        "name": flow.name,
        "description": flow.description,
        "step_count": len(flow.steps),
        "is_enabled": flow.is_enabled,
        "created_at": flow.created_at.isoformat(),
        "updated_at": flow.updated_at.isoformat(),
    }


@router.delete("/{flow_id}", status_code=204)
async def delete_flow(
    flow_id: uuid.UUID,
    tenant_id: str = Depends(get_tenant_id),
    session: AsyncSession = Depends(get_session),
) -> None:
    """
    Delete a script flow.
    """
    logger.info(f"Deleting flow for tenant={tenant_id}, id={flow_id}")

    service = ScriptFlowService(session)
    success = await service.delete_flow(tenant_id, flow_id)

    if not success:
        raise HTTPException(status_code=404, detail="Flow not found")