from pathlib import Path

from django.conf import settings
from django.core.management.base import BaseCommand, CommandError
from django.db.models import Count


class Command(BaseCommand):
    help = "Render a PrintingOrder into a .docx template using real DB data (pick the most 'full' order by default)."

    def add_arguments(self, parser):
        parser.add_argument(
            "--order-id",
            type=int,
            default=None,
            help="指定 PrintingOrder.id；不传则自动选择 PrintingJob 明细最多的一单",
        )
        parser.add_argument(
            "--template",
            type=str,
            default=str(Path(settings.BASE_DIR) / "print-template.docx"),
            help="docx 模板路径（默认 BASE_DIR/print-template.docx）",
        )
        parser.add_argument(
            "--out",
            type=str,
            default="",
            help="输出 docx 路径（默认 .tmp_docx/printing-order-{id}.docx）",
        )
        parser.add_argument(
            "--printer",
            type=str,
            default="系统自动生成",
            help="填充 {打印人}",
        )
        parser.add_argument(
            "--keep-unresolved",
            action="store_true",
            help="不清空未命中的占位符（默认会清空）",
        )

    def handle(self, *args, **options):
        order_id = options.get("order_id")
        template = str(options.get("template") or "")
        out = str(options.get("out") or "")
        printer = str(options.get("printer") or "")
        keep_unresolved = bool(options.get("keep_unresolved"))

        tp = Path(template)
        if not tp.exists():
            raise CommandError(f"模板文件不存在：{template}")
        if tp.suffix.lower() != ".docx":
            raise CommandError("template 必须是 .docx 文件")

        from printing.models import PrintingOrder

        qs = PrintingOrder.objects.all()
        if order_id:
            order = (
                qs.select_related("customer", "merchant", "process")
                .prefetch_related("printing_jobs__product")
                .filter(id=int(order_id))
                .first()
            )
            if not order:
                raise CommandError(f"PrintingOrder 不存在：id={order_id}")
        else:
            order = (
                qs.annotate(job_count=Count("printing_jobs"))
                .filter(job_count__gt=0)
                .order_by("-job_count", "-id")
                .select_related("customer", "merchant", "process")
                .prefetch_related("printing_jobs__product")
                .first()
            )
            if not order:
                raise CommandError("未找到包含 printing_jobs 的 PrintingOrder（无法做“饱满”渲染测试）")

        # output path default
        if not out:
            out = str(Path(settings.BASE_DIR) / ".tmp_docx" / f"printing-order-{order.id}.docx")
        Path(out).parent.mkdir(parents=True, exist_ok=True)

        from printing.docx_template import extract_docx_placeholders, render_docx_template
        from printing.print_docx_services import build_debug_context_summary, build_printing_order_docx_context

        placeholders = extract_docx_placeholders(template_path=str(tp))
        ctx = build_printing_order_docx_context(order=order, placeholders=placeholders, printer_label=printer)
        ctx_stats = build_debug_context_summary(ctx)

        stats = render_docx_template(
            template_path=str(tp),
            output_path=str(out),
            context=ctx,
            clear_unresolved=(not keep_unresolved),
        )

        job_count = order.printing_jobs.count()
        self.stdout.write(
            self.style.SUCCESS(
                "渲染完成："
                f" order_id={order.id}"
                f" job_count={job_count}"
                f" out={out}"
                f" paragraphs_touched={stats.paragraphs_touched}"
                f" placeholders_replaced_or_cleared={stats.placeholders_replaced_or_cleared}"
                f" context_filled={ctx_stats['context_filled_keys']}/{ctx_stats['context_total_keys']}"
            )
        )