from fastapi import APIRouter, Depends, Query, HTTPException, UploadFile, File, Form
from fastapi.responses import Response
from fastapi.responses import RedirectResponse
from typing import Optional

from auth.models import TokenPayload
from auth.dependencies import require_permission
from manufacturing.models import (
    BatchCreate, BatchResponse,
    DeviceInventoryItem, DeviceInventoryListResponse,
    DeviceStatusUpdate, DeviceAssign,
    ManufacturingStats,
)
from manufacturing import service
from manufacturing import audit
from shared.exceptions import NotFoundError

VALID_FLASH_ASSETS = {"bootloader.bin", "partitions.bin"}
VALID_HW_TYPES_MFG = {"vesper", "vesper_plus", "vesper_pro", "agnus", "agnus_mini", "chronos", "chronos_pro"}

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


@router.get("/stats", response_model=ManufacturingStats)
def get_stats(
    _user: TokenPayload = Depends(require_permission("manufacturing", "view")),
):
    return service.get_stats()


@router.get("/audit-log")
async def get_audit_log(
    limit: int = Query(20, ge=1, le=100),
    _user: TokenPayload = Depends(require_permission("manufacturing", "view")),
):
    entries = await audit.get_recent(limit=limit)
    return {"entries": entries}


@router.post("/batch", response_model=BatchResponse, status_code=201)
async def create_batch(
    body: BatchCreate,
    user: TokenPayload = Depends(require_permission("manufacturing", "add")),
):
    result = service.create_batch(body)
    await audit.log_action(
        admin_user=user.email,
        action="batch_created",
        detail={
            "batch_id": result.batch_id,
            "board_type": result.board_type,
            "board_version": result.board_version,
            "quantity": len(result.serial_numbers),
        },
    )
    return result


@router.get("/devices", response_model=DeviceInventoryListResponse)
def list_devices(
    status: Optional[str] = Query(None),
    hw_type: Optional[str] = Query(None),
    search: Optional[str] = Query(None),
    limit: int = Query(100, ge=1, le=500),
    offset: int = Query(0, ge=0),
    _user: TokenPayload = Depends(require_permission("manufacturing", "view")),
):
    items = service.list_devices(
        status=status,
        hw_type=hw_type,
        search=search,
        limit=limit,
        offset=offset,
    )
    return DeviceInventoryListResponse(devices=items, total=len(items))


@router.get("/devices/{sn}", response_model=DeviceInventoryItem)
def get_device(
    sn: str,
    _user: TokenPayload = Depends(require_permission("manufacturing", "view")),
):
    return service.get_device_by_sn(sn)


@router.patch("/devices/{sn}/status", response_model=DeviceInventoryItem)
async def update_status(
    sn: str,
    body: DeviceStatusUpdate,
    user: TokenPayload = Depends(require_permission("manufacturing", "edit")),
):
    result = service.update_device_status(sn, body)
    await audit.log_action(
        admin_user=user.email,
        action="status_updated",
        serial_number=sn,
        detail={"status": body.status.value, "note": body.note},
    )
    return result


@router.get("/devices/{sn}/nvs.bin")
async def download_nvs(
    sn: str,
    user: TokenPayload = Depends(require_permission("manufacturing", "view")),
):
    binary = service.get_nvs_binary(sn)
    await audit.log_action(
        admin_user=user.email,
        action="device_flashed",
        serial_number=sn,
    )
    return Response(
        content=binary,
        media_type="application/octet-stream",
        headers={"Content-Disposition": f'attachment; filename="{sn}_nvs.bin"'},
    )


@router.post("/devices/{sn}/assign", response_model=DeviceInventoryItem)
async def assign_device(
    sn: str,
    body: DeviceAssign,
    user: TokenPayload = Depends(require_permission("manufacturing", "edit")),
):
    result = service.assign_device(sn, body)
    await audit.log_action(
        admin_user=user.email,
        action="device_assigned",
        serial_number=sn,
        detail={"customer_email": body.customer_email, "customer_name": body.customer_name},
    )
    return result


@router.delete("/devices/{sn}", status_code=204)
async def delete_device(
    sn: str,
    force: bool = Query(False, description="Required to delete sold/claimed devices"),
    user: TokenPayload = Depends(require_permission("manufacturing", "delete")),
):
    """Delete a device. Sold/claimed devices require force=true."""
    try:
        service.delete_device(sn, force=force)
    except NotFoundError:
        raise HTTPException(status_code=404, detail="Device not found")
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))
    await audit.log_action(
        admin_user=user.email,
        action="device_deleted",
        serial_number=sn,
        detail={"force": force},
    )


@router.delete("/devices", status_code=200)
async def delete_unprovisioned(
    user: TokenPayload = Depends(require_permission("manufacturing", "delete")),
):
    """Delete all devices with status 'manufactured' (never provisioned)."""
    deleted = service.delete_unprovisioned_devices()
    await audit.log_action(
        admin_user=user.email,
        action="bulk_delete_unprovisioned",
        detail={"count": len(deleted), "serial_numbers": deleted},
    )
    return {"deleted": deleted, "count": len(deleted)}


@router.get("/devices/{sn}/firmware.bin")
def redirect_firmware(
    sn: str,
    _user: TokenPayload = Depends(require_permission("manufacturing", "view")),
):
    """Redirect to the latest stable firmware binary for this device's hw_type.
    Resolves to GET /api/firmware/{hw_type}/stable/{version}/firmware.bin.
    """
    url = service.get_firmware_url(sn)
    return RedirectResponse(url=url, status_code=302)


# ─────────────────────────────────────────────────────────────────────────────
# Flash assets — bootloader.bin and partitions.bin per hw_type
# These are the binaries that must be flashed at fixed addresses during full
# provisioning (0x1000 bootloader, 0x8000 partition table).
# They are NOT flashed during OTA updates — only during initial provisioning.
# Upload once per hw_type after each PlatformIO build that changes the layout.
# ─────────────────────────────────────────────────────────────────────────────

@router.post("/flash-assets/{hw_type}/{asset}", status_code=204)
async def upload_flash_asset(
    hw_type: str,
    asset: str,
    file: UploadFile = File(...),
    _user: TokenPayload = Depends(require_permission("manufacturing", "add")),
):
    """Upload a bootloader.bin or partitions.bin for a given hw_type.

    These are build artifacts from PlatformIO (.pio/build/{env}/bootloader.bin
    and .pio/build/{env}/partitions.bin). Upload them once per hw_type after
    each PlatformIO build that changes the partition layout.
    """
    if hw_type not in VALID_HW_TYPES_MFG:
        raise HTTPException(status_code=400, detail=f"Invalid hw_type. Must be one of: {', '.join(sorted(VALID_HW_TYPES_MFG))}")
    if asset not in VALID_FLASH_ASSETS:
        raise HTTPException(status_code=400, detail=f"Invalid asset. Must be one of: {', '.join(sorted(VALID_FLASH_ASSETS))}")
    data = await file.read()
    service.save_flash_asset(hw_type, asset, data)


@router.get("/devices/{sn}/bootloader.bin")
def download_bootloader(
    sn: str,
    _user: TokenPayload = Depends(require_permission("manufacturing", "view")),
):
    """Return the bootloader.bin for this device's hw_type (flashed at 0x1000)."""
    item = service.get_device_by_sn(sn)
    try:
        data = service.get_flash_asset(item.hw_type, "bootloader.bin")
    except NotFoundError as e:
        raise HTTPException(status_code=404, detail=str(e))
    return Response(
        content=data,
        media_type="application/octet-stream",
        headers={"Content-Disposition": f'attachment; filename="bootloader_{item.hw_type}.bin"'},
    )


@router.get("/devices/{sn}/partitions.bin")
def download_partitions(
    sn: str,
    _user: TokenPayload = Depends(require_permission("manufacturing", "view")),
):
    """Return the partitions.bin for this device's hw_type (flashed at 0x8000)."""
    item = service.get_device_by_sn(sn)
    try:
        data = service.get_flash_asset(item.hw_type, "partitions.bin")
    except NotFoundError as e:
        raise HTTPException(status_code=404, detail=str(e))
    return Response(
        content=data,
        media_type="application/octet-stream",
        headers={"Content-Disposition": f'attachment; filename="partitions_{item.hw_type}.bin"'},
    )