"""ObjectScale / S3 storage API for Command Center."""

from __future__ import annotations

import os
from typing import Any

import boto3
from botocore.client import Config
from botocore.exceptions import ClientError
from fastapi import APIRouter, Query
from fastapi.responses import JSONResponse, StreamingResponse

S3_ENDPOINT = os.getenv("S3_ENDPOINT", "http://10.0.20.111:9020")
S3_ACCESS_KEY = os.getenv("S3_ACCESS_KEY", "object_admin1")
S3_SECRET_KEY = os.getenv("S3_SECRET_KEY", "ChangeMeChangeMeChangeMeChangeMeChangeMe")
S3_REGION = os.getenv("S3_REGION", "us-east-1")

router = APIRouter(prefix="/api/storage/s3", tags=["storage"])


def _client():
    return boto3.client(
        "s3",
        endpoint_url=S3_ENDPOINT,
        aws_access_key_id=S3_ACCESS_KEY,
        aws_secret_access_key=S3_SECRET_KEY,
        region_name=S3_REGION,
        config=Config(signature_version="s3v4", s3={"addressing_style": "path"}),
    )


def _human_size(n: int) -> str:
    for unit in ("B", "KB", "MB", "GB", "TB"):
        if n < 1024:
            return f"{n:.0f} {unit}" if unit == "B" else f"{n:.1f} {unit}"
        n /= 1024
    return f"{n:.1f} PB"


@router.get("/health")
async def s3_health():
    try:
        s3 = _client()
        buckets = s3.list_buckets()
        names = [b["Name"] for b in buckets.get("Buckets", [])]
        return {
            "ok": True,
            "endpoint": S3_ENDPOINT,
            "buckets": len(names),
            "bucket_names": names,
        }
    except Exception as exc:
        return JSONResponse({"ok": False, "endpoint": S3_ENDPOINT, "error": str(exc)}, status_code=502)


@router.get("/buckets")
async def list_buckets():
    try:
        s3 = _client()
        resp = s3.list_buckets()
        items = []
        for b in resp.get("Buckets", []):
            name = b["Name"]
            try:
                loc = s3.list_objects_v2(Bucket=name, MaxKeys=1)
                count_hint = loc.get("KeyCount", 0)
            except ClientError:
                count_hint = None
            items.append({
                "name": name,
                "created": b.get("CreationDate", "").isoformat() if b.get("CreationDate") else None,
                "has_objects": bool(count_hint),
            })
        return {"ok": True, "buckets": items, "endpoint": S3_ENDPOINT}
    except Exception as exc:
        return JSONResponse({"ok": False, "error": str(exc)}, status_code=502)


@router.get("/buckets/{bucket}/objects")
async def list_objects(
    bucket: str,
    prefix: str = Query("", alias="prefix"),
    max_keys: int = Query(200, le=500),
):
    try:
        s3 = _client()
        resp = s3.list_objects_v2(Bucket=bucket, Prefix=prefix, Delimiter="/", MaxKeys=max_keys)
        folders = [
            {"type": "prefix", "name": p["Prefix"][len(prefix):].rstrip("/"), "prefix": p["Prefix"]}
            for p in resp.get("CommonPrefixes", [])
        ]
        objects = [
            {
                "type": "object",
                "key": o["Key"],
                "name": o["Key"][len(prefix):] if o["Key"].startswith(prefix) else o["Key"],
                "size": o.get("Size", 0),
                "size_human": _human_size(o.get("Size", 0)),
                "modified": o.get("LastModified", "").isoformat() if o.get("LastModified") else None,
            }
            for o in resp.get("Contents", [])
            if o["Key"] != prefix
        ]
        return {
            "ok": True,
            "bucket": bucket,
            "prefix": prefix,
            "folders": folders,
            "objects": objects,
            "truncated": resp.get("IsTruncated", False),
        }
    except ClientError as exc:
        return JSONResponse({"ok": False, "error": str(exc)}, status_code=403)
    except Exception as exc:
        return JSONResponse({"ok": False, "error": str(exc)}, status_code=502)


@router.get("/buckets/{bucket}/download")
async def download_object(bucket: str, key: str = Query(...)):
    try:
        s3 = _client()
        obj = s3.get_object(Bucket=bucket, Key=key)
        body = obj["Body"]
        filename = key.split("/")[-1] or "download"
        media = obj.get("ContentType") or "application/octet-stream"

        def stream():
            while chunk := body.read(1024 * 256):
                yield chunk

        return StreamingResponse(
            stream(),
            media_type=media,
            headers={"Content-Disposition": f'attachment; filename="{filename}"'},
        )
    except ClientError as exc:
        return JSONResponse({"ok": False, "error": str(exc)}, status_code=404)