#!/usr/bin/env python3
from __future__ import annotations

import argparse
import json
from datetime import datetime
from pathlib import Path

from build_generated_mcp_graph import (
    DEFAULT_HELP_ROOT,
    DEFAULT_MCP_ROOT,
    DEFAULT_OUTPUT_ROOT,
    build_graph,
    load_server_catalog,
)
from biomni.graph import GraphRouter, ToolGraph, ToolSchemaExtractor
from biomni.model.query_rewriter import QueryRewriter
from biomni.model.retriever import ToolRetriever


PROJECT_ROOT = Path(__file__).resolve().parent
DEFAULT_PLAN_ROOT = PROJECT_ROOT / "query_graph_plans"


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(
        description=(
            "Read a user query, rewrite it into a retrieval-friendly prompt, "
            "and generate a graph-based MCP subgraph call chain."
        )
    )
    parser.add_argument("--query", default="", help="Natural-language task query.")
    parser.add_argument("--query-file", default="", help="Optional text/markdown file containing the query.")
    parser.add_argument(
        "--graph-dir",
        default="",
        help="Optional prebuilt graph directory containing server_catalog.json.",
    )
    parser.add_argument(
        "--mcp-root",
        default=str(DEFAULT_MCP_ROOT),
        help="MCP root for graph building when --graph-dir is not provided.",
    )
    parser.add_argument(
        "--help-root",
        default=str(DEFAULT_HELP_ROOT),
        help="Help text root for graph building when --graph-dir is not provided.",
    )
    parser.add_argument(
        "--graph-output-root",
        default=str(DEFAULT_OUTPUT_ROOT),
        help="Output root for graph building when --graph-dir is not provided.",
    )
    parser.add_argument(
        "--output-root",
        default=str(DEFAULT_PLAN_ROOT),
        help="Directory to store rewritten prompt and graph routing artifacts.",
    )
    parser.add_argument("--run-name", default="", help="Optional run folder name.")
    parser.add_argument(
        "--top-k-servers",
        type=int,
        default=8,
        help="How many servers to keep in the routed subgraph.",
    )
    parser.add_argument(
        "--candidate-pool",
        type=int,
        default=24,
        help="Candidate server pool size before truncating to top-k.",
    )
    parser.add_argument(
        "--top-k-tools",
        type=int,
        default=12,
        help="How many tools to keep per selected server.",
    )
    parser.add_argument(
        "--executable-only",
        action="store_true",
        help="Only include servers with non-empty server_meta.command in routing.",
    )
    return parser.parse_args()


def resolve_query(args: argparse.Namespace) -> str:
    parts: list[str] = []
    if args.query.strip():
        parts.append(args.query.strip())

    if args.query_file:
        query_path = Path(args.query_file).expanduser().resolve()
        if not query_path.exists():
            raise FileNotFoundError(f"Query file does not exist: {query_path}")
        parts.append(query_path.read_text(encoding="utf-8").strip())

    query = "\n\n".join(part for part in parts if part)
    if not query:
        raise ValueError("Please provide --query or --query-file.")
    return query


def prepare_graph_catalog(args: argparse.Namespace) -> tuple[Path, list[dict]]:
    if args.graph_dir:
        graph_dir = Path(args.graph_dir).expanduser().resolve()
        if not graph_dir.exists():
            raise FileNotFoundError(f"Graph directory does not exist: {graph_dir}")
    else:
        graph_dir = build_graph(
            mcp_root=Path(args.mcp_root).expanduser().resolve(),
            help_root=Path(args.help_root).expanduser().resolve(),
            output_root=Path(args.graph_output_root).expanduser().resolve(),
        )

    server_entries = load_server_catalog(graph_dir)
    if args.executable_only:
        server_entries = [
            entry
            for entry in server_entries
            if entry.get("command_available") or entry.get("server_meta", {}).get("command")
        ]
    if not server_entries:
        raise RuntimeError("No MCP server entries available for graph routing.")
    return graph_dir, server_entries


def build_rewritten_prompt(query_context: dict, graph_dir: Path, server_count: int) -> str:
    subtasks = query_context.get("subtasks", [])
    subtasks_text = "\n".join(f"- {step}" for step in subtasks) if subtasks else "- No explicit subtasks inferred."
    categories = ", ".join(query_context.get("categories", [])) or "general_biomedical_analysis"
    server_hints = ", ".join(query_context.get("server_hints", [])) or "none"

    return (
        "You are planning a graph-guided MCP workflow from a user query.\n\n"
        f"Original query:\n{query_context.get('original_query', '').strip()}\n\n"
        f"Task summary:\n{query_context.get('task_summary', '').strip()}\n\n"
        f"Rewritten retrieval query:\n{query_context.get('retrieval_query', '').strip()}\n\n"
        f"Inferred categories: {categories}\n"
        f"Server hints: {server_hints}\n\n"
        "Planned subtasks:\n"
        f"{subtasks_text}\n\n"
        "Graph constraints:\n"
        f"- Graph directory: {graph_dir}\n"
        f"- Indexed server count: {server_count}\n"
        "- Route through ToolGraph/GraphRouter to get a minimal MCP subgraph call chain.\n"
    )


def format_call_chain(route_result: dict) -> str:
    lines = ["# Graph Subgraph Call Chain", ""]
    execution_plan = route_result.get("execution_plan", [])
    workflow_subgraph = route_result.get("workflow_subgraph", [])
    seed_nodes = route_result.get("seed_nodes", [])
    selected_servers = route_result.get("selected_servers", [])

    lines.append("## Seed Nodes")
    if seed_nodes:
        lines.extend(f"- {node_id}" for node_id in seed_nodes)
    else:
        lines.append("- (none)")
    lines.append("")

    lines.append("## Execution Plan")
    if execution_plan:
        for index, step in enumerate(execution_plan, start=1):
            tools = ", ".join(step.get("tools", [])) or "(no tools)"
            lines.append(
                f"{index}. stage={step.get('stage', 'analysis')} | "
                f"server={step.get('server', 'unknown')} | tools={tools}"
            )
    else:
        lines.append("1. No staged plan was produced from the current query/graph.")
    lines.append("")

    lines.append("## Workflow Subgraph")
    if workflow_subgraph:
        for node in workflow_subgraph:
            tools = ", ".join(node.get("tools", [])) or "(no tools)"
            lines.append(
                f"- server={node.get('server')} | category={node.get('category')} "
                f"| score={node.get('score', 0):.2f} | tools={tools}"
            )
    else:
        lines.append("- (none)")
    lines.append("")

    lines.append("## Server Selection Reasons")
    if selected_servers:
        for server in selected_servers:
            reasons = server.get("graph_reason", [])
            if reasons:
                lines.append(f"- {server.get('name')}: {'; '.join(reasons)}")
            else:
                lines.append(f"- {server.get('name')}: (no explicit reasons)")
    else:
        lines.append("- (none)")
    lines.append("")
    return "\n".join(lines)


def make_run_dir(output_root: Path, run_name: str) -> Path:
    if run_name.strip():
        folder = run_name.strip()
    else:
        folder = datetime.now().strftime("query_plan_%Y%m%d_%H%M%S")
    run_dir = output_root / folder
    run_dir.mkdir(parents=True, exist_ok=True)
    return run_dir


def main() -> None:
    args = parse_args()
    query = resolve_query(args)
    graph_dir, server_entries = prepare_graph_catalog(args)

    rewriter = QueryRewriter()
    query_context = rewriter.rewrite(query, llm=None)

    schema_extractor = ToolSchemaExtractor()
    tool_graph = ToolGraph(schema_extractor=schema_extractor)
    tool_graph.build_from_server_entries(server_entries)

    router = GraphRouter(schema_extractor=schema_extractor)
    route_result = router.route(
        query_context=query_context,
        tool_graph=tool_graph,
        retriever=ToolRetriever(),
        llm=None,
        top_k_servers=args.top_k_servers,
        candidate_pool=args.candidate_pool,
        top_k_tools=args.top_k_tools,
    )

    rewritten_prompt = build_rewritten_prompt(
        query_context=query_context,
        graph_dir=graph_dir,
        server_count=len(server_entries),
    )
    call_chain_markdown = format_call_chain(route_result)

    output_root = Path(args.output_root).expanduser().resolve()
    run_dir = make_run_dir(output_root, args.run_name)

    rewritten_prompt_path = run_dir / "rewritten_prompt.txt"
    query_context_path = run_dir / "query_context.json"
    route_result_path = run_dir / "graph_route_result.json"
    call_chain_path = run_dir / "graph_subgraph_call_chain.md"
    run_meta_path = run_dir / "run_metadata.json"

    rewritten_prompt_path.write_text(rewritten_prompt, encoding="utf-8")
    query_context_path.write_text(json.dumps(query_context, ensure_ascii=False, indent=2), encoding="utf-8")
    route_result_path.write_text(json.dumps(route_result, ensure_ascii=False, indent=2), encoding="utf-8")
    call_chain_path.write_text(call_chain_markdown, encoding="utf-8")
    run_meta_path.write_text(
        json.dumps(
            {
                "query": query,
                "graph_dir": str(graph_dir),
                "server_count_for_routing": len(server_entries),
                "selected_server_count": len(route_result.get("selected_servers", [])),
                "seed_nodes_count": len(route_result.get("seed_nodes", [])),
                "top_k_servers": args.top_k_servers,
                "candidate_pool": args.candidate_pool,
                "top_k_tools": args.top_k_tools,
                "executable_only": args.executable_only,
            },
            ensure_ascii=False,
            indent=2,
        ),
        encoding="utf-8",
    )

    print("Query graph planning completed.")
    print(f"Run dir: {run_dir}")
    print(f"Rewritten prompt: {rewritten_prompt_path}")
    print(f"Query context: {query_context_path}")
    print(f"Graph route result: {route_result_path}")
    print(f"Subgraph call chain: {call_chain_path}")
    print(f"Run metadata: {run_meta_path}")


if __name__ == "__main__":
    main()