from fastapi import APIRouter, Depends, HTTPException
from fastapi.responses import FileResponse
from auth.models import TokenPayload
from auth.dependencies import require_permission
from builder.models import (
    BuiltMelodyCreate,
    BuiltMelodyUpdate,
    BuiltMelodyInDB,
    BuiltMelodyListResponse,
)
from builder import service

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


@router.get("", response_model=BuiltMelodyListResponse)
async def list_built_melodies(
    _user: TokenPayload = Depends(require_permission("melodies", "view")),
):
    melodies = await service.list_built_melodies()
    return BuiltMelodyListResponse(melodies=melodies, total=len(melodies))

@router.get("/for-melody/{firestore_melody_id}")
async def get_for_firestore_melody(
    firestore_melody_id: str,
    _user: TokenPayload = Depends(require_permission("melodies", "view")),
):
    """Get the built melody assigned to a given Firestore melody ID. Returns null if none found."""
    result = await service.get_built_melody_for_firestore_id(firestore_melody_id)
    if result is None:
        return None
    return result.model_dump()



@router.get("/{melody_id}", response_model=BuiltMelodyInDB)
async def get_built_melody(
    melody_id: str,
    _user: TokenPayload = Depends(require_permission("melodies", "view")),
):
    return await service.get_built_melody(melody_id)


@router.post("", response_model=BuiltMelodyInDB, status_code=201)
async def create_built_melody(
    body: BuiltMelodyCreate,
    _user: TokenPayload = Depends(require_permission("melodies", "edit")),
):
    return await service.create_built_melody(body)


@router.put("/{melody_id}", response_model=BuiltMelodyInDB)
async def update_built_melody(
    melody_id: str,
    body: BuiltMelodyUpdate,
    _user: TokenPayload = Depends(require_permission("melodies", "edit")),
):
    return await service.update_built_melody(melody_id, body)


@router.delete("/{melody_id}", status_code=204)
async def delete_built_melody(
    melody_id: str,
    _user: TokenPayload = Depends(require_permission("melodies", "delete")),
):
    await service.delete_built_melody(melody_id)


@router.post("/{melody_id}/build-binary", response_model=BuiltMelodyInDB)
async def build_binary(
    melody_id: str,
    _user: TokenPayload = Depends(require_permission("melodies", "edit")),
):
    """Build the .bsm binary file from the stored steps."""
    return await service.build_binary(melody_id)


@router.post("/{melody_id}/build-builtin", response_model=BuiltMelodyInDB)
async def build_builtin_code(
    melody_id: str,
    _user: TokenPayload = Depends(require_permission("melodies", "edit")),
):
    """Generate PROGMEM C code and store it in the database."""
    return await service.build_builtin_code(melody_id)


@router.get("/{melody_id}/download")
async def download_binary(
    melody_id: str,
    _user: TokenPayload = Depends(require_permission("melodies", "view")),
):
    """Download the .bsm binary file."""
    path = await service.get_binary_path(melody_id)
    if not path:
        raise HTTPException(status_code=404, detail="Binary not built yet for this melody")

    melody = await service.get_built_melody(melody_id)
    filename = f"{melody.pid or melody.name}.bsm"

    return FileResponse(
        path=str(path),
        media_type="application/octet-stream",
        filename=filename,
    )


@router.post("/{melody_id}/assign", response_model=BuiltMelodyInDB)
async def assign_to_melody(
    melody_id: str,
    firestore_melody_id: str,
    _user: TokenPayload = Depends(require_permission("melodies", "edit")),
):
    """Mark this built melody as assigned to a Firestore melody."""
    return await service.assign_to_melody(melody_id, firestore_melody_id)


@router.post("/{melody_id}/unassign", response_model=BuiltMelodyInDB)
async def unassign_from_melody(
    melody_id: str,
    firestore_melody_id: str,
    _user: TokenPayload = Depends(require_permission("melodies", "edit")),
):
    """Remove a Firestore melody assignment from this built melody."""
    return await service.unassign_from_melody(melody_id, firestore_melody_id)