import json

from django.contrib.auth.decorators import login_required
from django.conf import settings
from django.http import Http404, JsonResponse
from django.views.decorators.http import require_http_methods

from review_agent.models import ExportedSummaryFile, RegulatoryInfoPackageBatch, WorkflowNodeRun
from review_agent.regulatory_info_package.constants import WORKFLOW_TYPE
from review_agent.regulatory_info_package.services.input_select import select_instruction_input
from review_agent.regulatory_info_package.workflow import (
    create_regulatory_info_package_batch,
    start_regulatory_info_package_workflow,
)


@require_http_methods(["GET"])
def health(request):
    return JsonResponse({"workflow_type": WORKFLOW_TYPE, "status": "available"})


@login_required
@require_http_methods(["POST"])
def start(request):
    try:
        payload = json.loads(request.body.decode("utf-8") or "{}")
    except json.JSONDecodeError:
        return JsonResponse({"error": "JSON 格式错误。"}, status=400)
    from review_agent.models import Conversation

    conversation = Conversation.objects.filter(pk=payload.get("conversation_id"), user=request.user).first()
    if not conversation:
        raise Http404("对话不存在。")
    selection = select_instruction_input(conversation, str(payload.get("message") or ""))
    if selection.status != "selected":
        return JsonResponse(
            {"status": selection.status, "message": selection.message, "candidates": selection.candidates},
            status=400,
        )
    batch = create_regulatory_info_package_batch(
        conversation=conversation,
        user=request.user,
        source_attachment=selection.attachment,
        source_summary_batch=selection.source_summary_batch,
        source_summary_item_id=selection.source_summary_item_id,
        source_file_name=selection.file_name,
        source_storage_path=selection.storage_path,
    )
    start_regulatory_info_package_workflow(batch, async_run=getattr(settings, "REGULATORY_INFO_PACKAGE_ASYNC", True))
    return JsonResponse({"batch_id": batch.pk, "workflow_type": WORKFLOW_TYPE, "status": batch.status})


@login_required
@require_http_methods(["GET"])
def batch_status(request, batch_id: int):
    batch = RegulatoryInfoPackageBatch.objects.filter(
        pk=batch_id,
        conversation__user=request.user,
        is_deleted=False,
    ).first()
    if not batch:
        raise Http404("材料包批次不存在。")
    exports = ExportedSummaryFile.objects.filter(
        workflow_type=WORKFLOW_TYPE,
        workflow_batch_id=batch.pk,
    ).order_by("-export_type", "id")
    sorted_exports = sorted(exports, key=lambda item: 0 if item.export_type == ExportedSummaryFile.ExportType.ZIP else 1)
    return JsonResponse(
        {
            "batch": {
                "id": batch.pk,
                "workflow_type": WORKFLOW_TYPE,
                "batch_no": batch.batch_no,
                "status": batch.status,
                "product_name": batch.product_name,
                "risk_summary_text": _risk_summary_text(batch),
                "error_message": batch.error_message,
            },
            "nodes": [
                {
                    "node_code": node.node_code,
                    "node_name": node.node_name,
                    "status": node.status,
                    "progress": node.progress,
                    "message": node.message,
                }
                for node in WorkflowNodeRun.objects.filter(
                    workflow_type=WORKFLOW_TYPE,
                    workflow_batch_id=batch.pk,
                ).order_by("id")
            ],
            "exports": [
                {
                    "id": export.pk,
                    "export_type": export.export_type,
                    "export_category": export.export_category,
                    "file_name": export.file_name,
                    "download_url": f"/api/review-agent/file-summary/exports/{export.pk}/download/",
                }
                for export in sorted_exports
            ],
            "failed_files": [item for item in batch.generated_files if item.get("status") == "failed"],
            "notifications": [
                {
                    "id": item.pk,
                    "channel": item.channel,
                    "send_status": item.send_status,
                    "status_label": "通知已记录" if item.send_status == "success" else item.send_status,
                    "error_message": item.error_message,
                }
                for item in batch.notifications.filter(is_deleted=False).order_by("-created_at", "-id")
            ],
        }
    )


def _risk_summary_text(batch: RegulatoryInfoPackageBatch) -> str:
    parts = []
    if batch.missing_fields:
        parts.append(f"缺失字段 {len(batch.missing_fields)}")
    if batch.llm_only_fields:
        parts.append(f"LLM-only {len(batch.llm_only_fields)}")
    if batch.conflict_fields:
        parts.append(f"冲突字段 {len(batch.conflict_fields)}")
    if batch.risk_notes:
        parts.append(f"提示 {len(batch.risk_notes)}")
    return " · ".join(parts)