"""
GitRag Standalone Retriever — HuggingFace Spaces entrypoint.

Requires env vars:
  TURSO_DATABASE_URL  (or DATABASE_URL)
  TURSO_AUTH_TOKEN    (or DB_AUTH_TOKEN)
"""
import os
import sys
import time


def log_stage(message: str, start_time: float) -> None:
    elapsed = time.monotonic() - start_time
    print(f"[{elapsed:7.1f}s] {message}", flush=True)


def check_config():
    db_url = os.environ.get("TURSO_DATABASE_URL") or os.environ.get("DATABASE_URL")
    db_token = os.environ.get("TURSO_AUTH_TOKEN") or os.environ.get("DB_AUTH_TOKEN")

    if not db_url or not db_token:
        sys.stderr.write("\n")
        sys.stderr.write("!" * 60 + "\n")
        sys.stderr.write("!! FATAL ERROR: MISSING DATABASE CONFIGURATION             !!\n")
        sys.stderr.write("!!                                                         !!\n")
        sys.stderr.write("!! You must set the following Secrets in your Space:       !!\n")
        sys.stderr.write("!!   - TURSO_DATABASE_URL                                  !!\n")
        sys.stderr.write("!!   - TURSO_AUTH_TOKEN                                    !!\n")
        sys.stderr.write("!!                                                         !!\n")
        sys.stderr.write("!! Go to: Settings > Variables and secrets                 !!\n")
        sys.stderr.write("!" * 60 + "\n")
        sys.stderr.write("\n")
        sys.exit(1)
    return db_url, db_token


if __name__ == "__main__":
    start_time = time.monotonic()
    db_url, db_token = check_config()

    try:
        from Persistence.Persist import PersistInLibsql, LibsqlConfig
        from Retriever import Retriever, Reranker
        from Calculators.EmbeddingCalculator import EmbeddingCalculator
        from gitrag_mcp_server.server import create_mcp_server
    except ImportError as e:
        sys.stderr.write(f"FATAL: Failed to import GitRag modules: {e}\n")
        sys.exit(1)

    log_stage("GitRag standalone retriever starting", start_time)
    log_stage("Loading embedding model", start_time)
    calculator = EmbeddingCalculator()
    log_stage("Embedding model ready", start_time)

    log_stage("Connecting to LibSQL", start_time)
    cfg = LibsqlConfig.from_parts(database_url=db_url, auth_token=db_token)
    persistence = PersistInLibsql(cfg=cfg)
    log_stage("LibSQL connection ready", start_time)

    log_stage("Loading reranker", start_time)
    reranker = Reranker()
    log_stage("Reranker ready", start_time)

    retriever = Retriever(persistence, calculator, reranker=reranker)
    log_stage("Retriever ready", start_time)

    log_stage("Starting MCP server on port 7860", start_time)
    mcp = create_mcp_server(retriever=retriever)
    mcp.run(
        transport="http",
        port=7860,
        host="0.0.0.0",
        stateless_http=True,
        json_response=True,
        show_banner=False,
    )