"""
REST API Routes
===============
Health checks, cache management, and configuration endpoints.
"""

import io
import os
import sys
import zipfile
from pathlib import Path
from typing import List, Dict, Any

from fastapi import APIRouter, HTTPException, Query
from fastapi.responses import StreamingResponse
from pydantic import BaseModel

# Add project root and src/ to path for eurus package
PROJECT_ROOT = Path(__file__).parent.parent.parent
sys.path.insert(0, str(PROJECT_ROOT))
sys.path.insert(0, str(PROJECT_ROOT / "src"))

# IMPORT FROM EURUS PACKAGE
from eurus.config import CONFIG, ERA5_VARIABLES, GEOGRAPHIC_REGIONS

router = APIRouter()


class HealthResponse(BaseModel):
    status: str
    version: str
    agent_ready: bool


class DatasetInfo(BaseModel):
    variable: str
    query_type: str
    start_date: str
    end_date: str
    lat_bounds: tuple
    lon_bounds: tuple
    file_size_bytes: int
    path: str


class CacheResponse(BaseModel):
    datasets: List[Dict[str, Any]]
    total_size_bytes: int


class ConfigResponse(BaseModel):
    variables: List[Dict[str, str]]
    regions: List[str]
    model: str


@router.get("/keys-status")
async def keys_status():
    """Check which API keys are configured via environment variables."""
    return {
        "openai": bool(os.environ.get("OPENAI_API_KEY")),
        "arraylake": bool(os.environ.get("ARRAYLAKE_API_KEY")),
        "hf": bool(os.environ.get("HF_TOKEN")),
    }


@router.get("/health", response_model=HealthResponse)
async def health_check():
    """Check if the server is healthy."""
    # NOTE: We no longer check a shared singleton session.
    # Each WebSocket connection has its own AgentSession.
    return HealthResponse(
        status="ok",
        version="1.0.0",
        agent_ready=True  # Server is up → ready to accept WS connections
    )


@router.get("/cache", response_model=CacheResponse)
async def list_cache():
    """List all cached datasets."""
    from eurus.memory import get_memory

    memory = get_memory()
    datasets = []
    total_size = 0

    for path, record in memory.datasets.items():
        if os.path.exists(path):
            size = record.file_size_bytes
            if size == 0:
                # Calculate size if not recorded
                if os.path.isdir(path):
                    size = sum(
                        os.path.getsize(os.path.join(dp, f))
                        for dp, _, files in os.walk(path)
                        for f in files
                    )
                else:
                    size = os.path.getsize(path)

            datasets.append({
                "variable": record.variable,
                "query_type": record.query_type,
                "start_date": record.start_date,
                "end_date": record.end_date,
                "lat_bounds": record.lat_bounds,
                "lon_bounds": record.lon_bounds,
                "file_size_bytes": size,
                "path": path
            })
            total_size += size

    return CacheResponse(datasets=datasets, total_size_bytes=total_size)


@router.get("/cache/download")
async def download_dataset(path: str = Query(..., description="Path to Zarr dataset")):
    """Download a cached Zarr dataset as a ZIP archive."""
    dataset_path = Path(path).resolve()
    data_dir = (PROJECT_ROOT / "data").resolve()

    # Security: only allow paths under PROJECT_ROOT/data
    if not dataset_path.is_relative_to(data_dir):
        raise HTTPException(status_code=403, detail="Access denied: path outside data directory")

    if not dataset_path.exists():
        raise HTTPException(status_code=404, detail="Dataset not found")

    # Create ZIP in memory
    zip_buffer = io.BytesIO()
    with zipfile.ZipFile(zip_buffer, "w", zipfile.ZIP_DEFLATED) as zf:
        if dataset_path.is_dir():
            for file_path in dataset_path.rglob("*"):
                if file_path.is_file():
                    arcname = file_path.relative_to(dataset_path.parent)
                    zf.write(file_path, arcname)
        else:
            zf.write(dataset_path, dataset_path.name)

    zip_buffer.seek(0)
    filename = f"{dataset_path.name}.zip"

    return StreamingResponse(
        zip_buffer,
        media_type="application/zip",
        headers={"Content-Disposition": f'attachment; filename="{filename}"'}
    )


@router.get("/config", response_model=ConfigResponse)
async def get_config():
    """Get available variables and regions."""
    # Get unique variables
    seen_vars = set()
    variables = []
    for var_id, var_info in ERA5_VARIABLES.items():
        if var_info.short_name not in seen_vars:
            seen_vars.add(var_info.short_name)
            variables.append({
                "name": var_info.short_name,
                "long_name": var_info.long_name,
                "units": var_info.units,
                "description": var_info.description
            })

    regions = list(GEOGRAPHIC_REGIONS.keys())

    return ConfigResponse(
        variables=variables,
        regions=regions,
        model=CONFIG.model_name
    )


@router.delete("/conversation")
async def clear_conversation():
    """Clear the conversation history (shared memory only)."""
    from eurus.memory import get_memory

    memory = get_memory()
    memory.clear_conversation()

    # NOTE: Agent session messages are managed per-WebSocket connection.
    # Each session clears its own messages when the connection closes.

    return {"status": "ok", "message": "Conversation cleared"}


@router.get("/memory")
async def get_memory_summary():
    """Get memory summary."""
    from eurus.memory import get_memory

    memory = get_memory()

    return {
        "conversation_count": len(memory.conversations),
        "dataset_count": len([p for p in memory.datasets if os.path.exists(p)]),
        "analysis_count": len(memory.analyses),
        "context_summary": memory.get_context_summary()
    }