import json
import logging
import os
import asyncssh
from fastapi import APIRouter, Depends, HTTPException, BackgroundTasks, Query
import config

router = APIRouter()
logger = logging.getLogger(__name__)

# Absolute paths to media-mgmt scripts on NAS host
HEALTH_CHECK_SCRIPT = "/volume1/homes/zjgump/media-mgmt/immich/scripts/health-check.sh"
STORAGE_REPORT_SCRIPT = "/volume1/homes/zjgump/media-mgmt/diagnostics/storage-report.sh"
SCAN_LIBRARY_SCRIPT = "/volume1/homes/zjgump/media-mgmt/immich/scripts/scan-library.sh"
THUMBNAIL_CLINIC_SCRIPT = "/volume1/homes/zjgump/media-mgmt/diagnostics/thumbnail-clinic.sh"
SHUTTLE_SCRIPT = "/volume1/homes/zjgump/media-mgmt/transfer/ssd-shuttle.sh"
PHONE_INGEST_SCRIPT = "/volume1/homes/zjgump/media-mgmt/transfer/phone-to-nas.sh"

LOG_DIR = "/volume1/homes/zjgump/media-mgmt/logs"

async def run_host_command(cmd: str) -> tuple[int, str, str]:
    """Execute a command on the NAS host via SSH."""
    try:
        # Prepend PATH and NAS_HOST variables for host execution
        full_cmd = f'PATH="/volume1/homes/zjgump/bin:$PATH" NAS_HOST="naslan" {cmd}'
        async with asyncssh.connect(
            config.SSH_HOST,
            username=config.SSH_USER,
            client_keys=[config.SSH_KEY_PATH],
            known_hosts=None
        ) as conn:
            result = await conn.run(full_cmd)
            return result.exit_status, result.stdout, result.stderr
    except Exception as e:
        logger.error(f"SSH command failed ({cmd}): {e}")
        return 999, "", str(e)

@router.get("/health")
async def get_health():
    """Runs health-check.sh and returns the exit status and stdout/stderr."""
    code, stdout, stderr = await run_host_command(f"bash {HEALTH_CHECK_SCRIPT}")
    return {
        "status": "ok" if code == 0 else "warning" if code == 1 else "error",
        "exit_code": code,
        "stdout": stdout,
        "stderr": stderr
    }

@router.get("/storage")
async def get_storage():
    """Runs storage-report.sh -j and returns the parsed JSON storage report."""
    code, stdout, stderr = await run_host_command(f"bash {STORAGE_REPORT_SCRIPT} -j")
    if code != 0:
        raise HTTPException(status_code=500, detail=f"Storage report failed: {stderr}")
    try:
        return json.loads(stdout)
    except json.JSONDecodeError:
        return {
            "error": "Failed to parse JSON from storage report",
            "raw_output": stdout,
            "stderr": stderr
        }

@router.post("/maintenance/scan")
async def run_scan(background_tasks: BackgroundTasks, library: str = Query(None)):
    """Triggers scan-library.sh in the background and writes stdout/stderr to scan.log."""
    cmd = f"bash {SCAN_LIBRARY_SCRIPT}"
    if library:
        cmd += f" {library}"
    
    log_file = f"{LOG_DIR}/scan.log"
    run_cmd = f"mkdir -p {LOG_DIR} && echo '=== Scan Started at $(date) ===' > {log_file} && nohup {cmd} >> {log_file} 2>&1 &"
    
    code, stdout, stderr = await run_host_command(run_cmd)
    if code != 0:
        raise HTTPException(status_code=500, detail=f"Failed to start scan: {stderr}")
    
    return {"message": "Scan started in background", "log_file": log_file}

@router.post("/maintenance/requeue")
async def run_requeue(background_tasks: BackgroundTasks):
    """Triggers thumbnail-clinic.sh -r in the background and writes stdout/stderr to requeue.log."""
    cmd = f"bash {THUMBNAIL_CLINIC_SCRIPT} -r"
    log_file = f"{LOG_DIR}/requeue.log"
    
    run_cmd = f"mkdir -p {LOG_DIR} && echo '=== Requeue Started at $(date) ===' > {log_file} && nohup {cmd} >> {log_file} 2>&1 &"
    
    code, stdout, stderr = await run_host_command(run_cmd)
    if code != 0:
        raise HTTPException(status_code=500, detail=f"Failed to start thumbnail requeue: {stderr}")
    
    return {"message": "Thumbnail requeue started in background", "log_file": log_file}

@router.get("/logs/{task_name}")
async def get_logs(task_name: str):
    """Reads logs for a task from /volume1/homes/zjgump/media-mgmt/logs/{task_name}.log."""
    if task_name not in ["scan", "requeue", "shuttle", "phone-ingest"]:
        raise HTTPException(status_code=400, detail="Invalid task name")
    
    log_path = f"/volume1/homes/zjgump/media-mgmt/logs/{task_name}.log"
    if not os.path.exists(log_path):
        return {"content": "No log file found."}
    
    try:
        with open(log_path, "r") as f:
            content = f.readlines()
            return {"content": "".join(content[-200:])}
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Failed to read log file: {e}")

@router.get("/status")
async def get_active_status():
    """Checks if any ingestion/maintenance processes are currently running on the host."""
    processes = {
        "scan": SCAN_LIBRARY_SCRIPT,
        "requeue": THUMBNAIL_CLINIC_SCRIPT,
        "shuttle": SHUTTLE_SCRIPT,
        "phone-ingest": PHONE_INGEST_SCRIPT
    }
    
    status = {}
    for name, script_path in processes.items():
        code, stdout, stderr = await run_host_command(f"pgrep -f {script_path}")
        status[name] = {
            "running": code == 0,
            "pid": stdout.strip() if code == 0 else None
        }
    return status