from django.contrib import messages
from django.shortcuts import get_object_or_404, redirect, render
from django.views.decorators.http import require_POST

from apps.scenarios.services import list_scenarios

from .forms import DocumentUploadForm
from .models import UploadedDocument
from .services import create_uploaded_document, index_document


def document_list(request):
    # 列表页只负责展示文档元数据和可执行操作，不处理入库细节。
    documents = UploadedDocument.objects.all()
    status_counts = {
        "uploaded": documents.filter(status=UploadedDocument.STATUS_UPLOADED).count(),
        "indexed": documents.filter(status=UploadedDocument.STATUS_INDEXED).count(),
        "failed": documents.filter(status=UploadedDocument.STATUS_FAILED).count(),
        "total": documents.count(),
    }
    processing_pipeline = [
        {"title": "原始文件接收", "detail": "校验格式、大小和场景归属后保存原件。"},
        {"title": "文本与表格抽取", "detail": "按 PDF / DOCX / MD / TXT 使用不同解析策略。"},
        {"title": "页数统计与可信度评估", "detail": "对 Word 页数采用估算与可信度标记。"},
        {"title": "章节点归类", "detail": "基于文件名、标题和正文线索识别 CH 节点。"},
        {"title": "切片与索引入库", "detail": "生成知识切片，供 RAG、规则定位和审计引用使用。"},
    ]
    exception_items = [
        {"level": "待确认", "title": "CH1.2 监管信息目录.docx", "detail": "目录页码与正文页数存在偏差，建议人工复核。"},
        {"level": "低可信度", "title": "目标产品说明书.docx", "detail": "Word 页数为估算值，表格抽取质量良好。"},
        {"level": "失败", "title": "沟通记录扫描件.pdf", "detail": "疑似扫描件，需补做 OCR 或重新上传清晰版。"},
    ]
    return render(
        request,
        "documents/document_list.html",
        {
            "documents": documents,
            "status_counts": status_counts,
            "processing_pipeline": processing_pipeline,
            "exception_items": exception_items,
        },
    )


def upload(request):
    # 上传成功后仅保存文件和元数据，是否入库由用户显式触发。
    if request.method == "POST":
        form = DocumentUploadForm(request.POST, request.FILES)
        if form.is_valid():
            create_uploaded_document(form.cleaned_data["scenario_id"], form.cleaned_data["file"])
            messages.success(request, "文件已上传，可继续执行入库。")
            return redirect("documents:list")
    else:
        form = DocumentUploadForm()
    return render(
        request,
        "documents/upload.html",
        {
            "form": form,
            "scenarios": list_scenarios(),
            "upload_checks": [
                "文件格式支持 PDF、DOCX、MD、TXT",
                "业务资料与法规依据资料需分开归属",
                "目录类文件会优先参与完整性校验",
                "上传完成后建议立即进入解析与入库流程",
            ],
        },
    )


@require_POST
def index(request, document_id: int):
    document = get_object_or_404(UploadedDocument, pk=document_id)
    document = index_document(document)
    if document.status == UploadedDocument.STATUS_INDEXED:
        messages.success(request, "文档入库成功，当前文档已可参与检索。")
    else:
        messages.error(request, "文档入库失败，请检查错误原因后重试。")
    return redirect("documents:list")