import json
from pathlib import Path

from django.core.management.base import BaseCommand, CommandError


class Command(BaseCommand):
    help = "Render a .docx template by replacing placeholders like #{...} / {...} using a JSON context mapping."

    def add_arguments(self, parser):
        parser.add_argument(
            "template",
            type=str,
            help="模板文件路径（.docx），例如 /home/f/coding/flower/print-template.docx",
        )
        parser.add_argument(
            "--out",
            type=str,
            default="rendered.docx",
            help="输出 docx 路径（默认 rendered.docx）",
        )
        parser.add_argument(
            "--context-json",
            type=str,
            default="{}",
            help="JSON 字符串，键为占位符内部文本（例如 打印-销售单（8*9）.客户名称）",
        )
        parser.add_argument(
            "--context-json-file",
            type=str,
            default=None,
            help="JSON 文件路径（优先级高于 --context-json）",
        )
        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):
        template = str(options["template"])
        out = str(options["out"])
        context_json = str(options["context_json"] or "{}")
        context_json_file = options.get("context_json_file")
        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")

        if context_json_file:
            jp = Path(str(context_json_file))
            if not jp.exists():
                raise CommandError(f"JSON 文件不存在：{context_json_file}")
            context = json.loads(jp.read_text("utf-8"))
        else:
            context = json.loads(context_json)

        if not isinstance(context, dict):
            raise CommandError("context 必须是 JSON object（字典）")

        from printing.docx_template import render_docx_template

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

        self.stdout.write(
            self.style.SUCCESS(
                f"渲染完成：out={out} paragraphs_touched={stats.paragraphs_touched} placeholders={stats.placeholders_replaced_or_cleared}"
            )
        )