from __future__ import annotations

import os
from pathlib import Path

from fastapi import FastAPI, HTTPException
from fastapi.responses import FileResponse
from fastapi.staticfiles import StaticFiles


SANDBOX_DIR = Path(__file__).resolve().parent
PROJECT_ROOT = SANDBOX_DIR.parents[2]
STATIC_DIR = SANDBOX_DIR / "static"
SHARED_STATIC_DIR = PROJECT_ROOT / "apps" / "web" / "vue3" / "static"
DATA_ROOT = Path(
    os.environ.get(
        "AF3_SANDBOX_DATA_ROOT",
        "/home/xzq/5090/00test/af3/af3_outputs/gcn4_dimer_demo",
    )
).resolve()
ALLOWED_SUFFIXES = {".cif", ".mmcif"}
MOLSTAR_VERSION = (
    STATIC_DIR / "vendor" / "molstar" / "VERSION"
).read_text(encoding="utf-8").strip()

app = FastAPI(title="AF3 Molstar Sandbox")
app.mount("/static", StaticFiles(directory=STATIC_DIR), name="static")
app.mount(
    "/shared-static",
    StaticFiles(directory=SHARED_STATIC_DIR),
    name="shared-static",
)


def resolve_structure(filename: str) -> Path:
    requested = Path(filename)
    if requested.name != filename or requested.suffix.lower() not in ALLOWED_SUFFIXES:
        raise HTTPException(status_code=404, detail="structure not found")
    candidate = (DATA_ROOT / filename).resolve()
    if candidate.parent != DATA_ROOT or not candidate.is_file():
        raise HTTPException(status_code=404, detail="structure not found")
    return candidate


@app.get("/")
def index() -> FileResponse:
    return FileResponse(SANDBOX_DIR / "index.html")


@app.get("/api/health")
def health() -> dict[str, object]:
    return {
        "status": "ok",
        "data_root": str(DATA_ROOT),
        "data_root_available": DATA_ROOT.is_dir(),
        "molstar_version": MOLSTAR_VERSION,
    }


@app.get("/api/structures")
def list_structures() -> dict[str, list[dict[str, object]]]:
    if not DATA_ROOT.is_dir():
        return {"structures": []}
    structures = [
        {"name": path.name, "size": path.stat().st_size}
        for path in DATA_ROOT.iterdir()
        if path.is_file() and path.suffix.lower() in ALLOWED_SUFFIXES
    ]
    structures.sort(key=lambda item: str(item["name"]))
    return {"structures": structures}


@app.get("/api/structures/{filename}")
def get_structure(filename: str) -> FileResponse:
    path = resolve_structure(filename)
    return FileResponse(
        path,
        media_type="chemical/x-mmcif",
        filename=path.name,
    )