from __future__ import annotations

import argparse
import sys
import urllib.error
from pathlib import Path

from common import call_chat_completion, read_json, search_lexical_index
from rag_profiles import resolve_rag_profile

ROOT = Path(__file__).resolve().parents[1]
DEFAULT_INDEX = ROOT / "plugins" / "1c" / "datasets" / "prepared" / "rag_index.json"
DEFAULT_SYSTEM_PROMPT = ROOT / "plugins" / "1c" / "prompts" / "system.md"
DEFAULT_RAG_PROMPT = ROOT / "plugins" / "1c" / "prompts" / "rag-answer.md"


def format_context(results: list[dict], *, max_chars: int = 12000) -> str:
    if not results:
        return "Контекст не найден."

    blocks = []
    used_chars = 0
    for position, result in enumerate(results, start=1):
        document = result["document"]
        source = document.get("source_path") or "unknown"
        chunk = document.get("chunk_index")
        title = document.get("title") or "unknown"
        content = (document.get("content") or "").strip()
        header = f"[{position}] source={source} title={title} chunk={chunk} score={result['score']:.4f}"
        remaining = max_chars - used_chars - len(header) - 2
        if remaining <= 0:
            break
        if len(content) > remaining:
            content = content[: max(0, remaining - 3)].rstrip() + "..."
        block = "\n".join([header, content])
        blocks.append(block)
        used_chars += len(block) + 2
    return "\n\n".join(blocks)


def render_prompt(template_path: Path, context: str, question: str) -> str:
    template = template_path.read_text(encoding="utf-8")
    return template.replace("{{context}}", context).replace("{{question}}", question)


def main() -> int:
    parser = argparse.ArgumentParser(description="Ask the 1C RAG assistant.")
    parser.add_argument("question")
    parser.add_argument("--index", type=Path, default=DEFAULT_INDEX)
    parser.add_argument("--profile", default="auto")
    parser.add_argument("--limit", type=int)
    parser.add_argument("--candidate-limit", type=int)
    parser.add_argument("--dedupe-by-document", action="store_true")
    parser.add_argument("--min-score", type=float)
    parser.add_argument("--source-type", action="append", dest="source_types")
    parser.add_argument("--platform-version")
    parser.add_argument("--platform-doc-id")
    parser.add_argument("--max-context-chars", type=int)
    parser.add_argument("--base-url", help="OpenAI-compatible endpoint, for example http://docker-gpu.cin.su:8000")
    parser.add_argument("--model", default="qwen3-4b-instruct")
    parser.add_argument("--print-prompt", action="store_true", help="Print assembled prompt instead of calling a model.")
    parser.add_argument("--system-prompt", type=Path, default=DEFAULT_SYSTEM_PROMPT)
    parser.add_argument("--rag-prompt", type=Path, default=DEFAULT_RAG_PROMPT)
    args = parser.parse_args()

    index = read_json(args.index)
    profile = resolve_rag_profile(args.profile, args.question)
    source_types = args.source_types if args.source_types is not None else profile["source_types"]
    results = search_lexical_index(
        index,
        args.question,
        limit=int(args.limit or profile["limit"]),
        candidate_limit=int(args.candidate_limit or profile["candidate_limit"]),
        dedupe_by_document=args.dedupe_by_document or bool(profile["dedupe_by_document"]),
        min_score=float(args.min_score if args.min_score is not None else profile["min_score"]),
        source_types=source_types,
        metadata_filters={
            "platform_version": args.platform_version or "",
            "platform_doc_id": args.platform_doc_id or "",
        },
    )
    context = format_context(results, max_chars=int(args.max_context_chars or profile["max_context_chars"]))
    rag_prompt = render_prompt(args.rag_prompt, context=context, question=args.question)

    if args.print_prompt or not args.base_url:
        print(rag_prompt)
        if not args.base_url and not args.print_prompt:
            print(
                "\nNo --base-url provided, so only the prompt was rendered.",
                file=sys.stderr,
            )
        return 0

    system_prompt = args.system_prompt.read_text(encoding="utf-8")
    try:
        answer = call_chat_completion(
            base_url=args.base_url,
            model=args.model,
            messages=[
                {"role": "system", "content": system_prompt},
                {"role": "user", "content": rag_prompt},
            ],
            max_tokens=1200,
        )
    except (urllib.error.URLError, ValueError) as exc:
        print(f"Chat request failed: {exc}", file=sys.stderr)
        return 1

    print(answer)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())