from __future__ import annotations

import json
from typing import Literal
from fastapi import APIRouter, Depends, File as FastAPIFile, Form, UploadFile
from sqlalchemy.orm import Session

from govoplan_core.auth import ApiPrincipal, require_scope
from govoplan_files.backend.schemas import (
    ConflictResolutionRequest,
    FileUploadResponse,
    _conflict_resolutions,
)
from govoplan_files.backend.db.models import FileAsset
from govoplan_core.db.session import get_session
from govoplan_files.backend.runtime import settings
from govoplan_files.backend.storage.paths import UnsafeFilePathError
from govoplan_files.backend.storage.archives import extract_zip_upload
from govoplan_files.backend.storage.common import FileStorageError
from govoplan_files.backend.storage.connector_policy import (
    ConnectorPolicyDenied,
)
from govoplan_files.backend.storage.files import (
    create_file_asset,
)


from govoplan_files.backend.route_support import (
    _asset_response,
    _audit_connector_imports,
    _cleanup_temp_file,
    _connector_policy_error,
    _enforce_connector_policy,
    _http_error,
    _is_admin,
    _read_limited_upload,
    _source_metadata_from_form,
    _spool_limited_upload_to_temp,
)

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


@router.post("/upload", response_model=FileUploadResponse)
def upload_files(
    files: list[UploadFile] = FastAPIFile(...),
    owner_type: Literal["user", "group"] = Form(default="user"),
    owner_id: str | None = Form(default=None),
    path: str = Form(default=""),
    campaign_id: str | None = Form(default=None),
    unpack_zip: bool = Form(default=False),
    conflict_strategy: Literal["reject", "overwrite", "rename"] = Form(
        default="reject"
    ),
    conflict_resolutions_json: str | None = Form(default=None),
    source_provenance_json: str | None = Form(default=None),
    source_revision: str | None = Form(default=None),
    connector_policy_json: str | None = Form(default=None),
    session: Session = Depends(get_session),
    principal: ApiPrincipal = Depends(require_scope("files:file:upload")),
):
    target_owner = owner_id or principal.user.id
    uploaded_assets: list[FileAsset] = []
    try:
        raw_resolutions = (
            json.loads(conflict_resolutions_json) if conflict_resolutions_json else []
        )
        upload_resolutions = _conflict_resolutions(
            [ConflictResolutionRequest(**item) for item in raw_resolutions]
        )
        _enforce_connector_policy(
            source_provenance_json, connector_policy_json, operation="import"
        )
        metadata = _source_metadata_from_form(source_provenance_json, source_revision)
        for upload in files:
            filename = upload.filename or "file"
            content_type = upload.content_type or None
            upload_limit = (
                settings.file_upload_zip_max_bytes
                if unpack_zip and filename.lower().endswith(".zip")
                else settings.file_upload_max_bytes
            )
            if unpack_zip and filename.lower().endswith(".zip"):
                zip_path = _spool_limited_upload_to_temp(
                    upload, max_bytes=upload_limit, suffix=".zip"
                )
                try:
                    extracted = extract_zip_upload(
                        session,
                        tenant_id=principal.tenant_id,
                        owner_type=owner_type,
                        owner_id=target_owner,
                        user_id=principal.user.id,
                        zip_data=zip_path,
                        folder=path,
                        campaign_id=campaign_id,
                        conflict_strategy=conflict_strategy,
                        conflict_resolutions=upload_resolutions,
                        metadata=metadata,
                        is_admin=_is_admin(principal),
                        max_file_bytes=settings.file_upload_max_bytes,
                        max_total_bytes=settings.file_upload_zip_max_bytes,
                    )
                finally:
                    _cleanup_temp_file(zip_path)
                uploaded_assets.extend(item.asset for item in extracted)
                continue
            data = _read_limited_upload(upload, max_bytes=upload_limit)
            stored = create_file_asset(
                session,
                tenant_id=principal.tenant_id,
                owner_type=owner_type,
                owner_id=target_owner,
                user_id=principal.user.id,
                filename=filename,
                data=data,
                folder=path,
                content_type=content_type,
                campaign_id=campaign_id,
                conflict_strategy=conflict_strategy,
                conflict_resolutions=upload_resolutions,
                metadata=metadata,
                is_admin=_is_admin(principal),
            )
            uploaded_assets.append(stored.asset)
        _audit_connector_imports(session, principal, uploaded_assets)
        session.commit()
    except ConnectorPolicyDenied as exc:
        session.rollback()
        raise _connector_policy_error(exc) from exc
    except (FileStorageError, UnsafeFilePathError, ValueError) as exc:
        session.rollback()
        raise _http_error(exc) from exc
    return FileUploadResponse(
        files=[
            _asset_response(session, asset, include_shares=True)
            for asset in uploaded_assets
        ]
    )


@router.post("/upload-zip", response_model=FileUploadResponse)
def upload_zip(
    file: UploadFile = FastAPIFile(...),
    owner_type: Literal["user", "group"] = Form(default="user"),
    owner_id: str | None = Form(default=None),
    path: str = Form(default=""),
    campaign_id: str | None = Form(default=None),
    conflict_strategy: Literal["reject", "overwrite", "rename"] = Form(
        default="reject"
    ),
    conflict_resolutions_json: str | None = Form(default=None),
    source_provenance_json: str | None = Form(default=None),
    source_revision: str | None = Form(default=None),
    connector_policy_json: str | None = Form(default=None),
    session: Session = Depends(get_session),
    principal: ApiPrincipal = Depends(require_scope("files:file:upload")),
):
    target_owner = owner_id or principal.user.id
    zip_path: str | None = None
    try:
        raw_resolutions = (
            json.loads(conflict_resolutions_json) if conflict_resolutions_json else []
        )
        upload_resolutions = _conflict_resolutions(
            [ConflictResolutionRequest(**item) for item in raw_resolutions]
        )
        _enforce_connector_policy(
            source_provenance_json, connector_policy_json, operation="import"
        )
        metadata = _source_metadata_from_form(source_provenance_json, source_revision)
        zip_path = _spool_limited_upload_to_temp(
            file, max_bytes=settings.file_upload_zip_max_bytes, suffix=".zip"
        )
        extracted = extract_zip_upload(
            session,
            tenant_id=principal.tenant_id,
            owner_type=owner_type,
            owner_id=target_owner,
            user_id=principal.user.id,
            zip_data=zip_path,
            folder=path,
            campaign_id=campaign_id,
            conflict_strategy=conflict_strategy,
            conflict_resolutions=upload_resolutions,
            metadata=metadata,
            is_admin=_is_admin(principal),
            max_file_bytes=settings.file_upload_max_bytes,
            max_total_bytes=settings.file_upload_zip_max_bytes,
        )
        _audit_connector_imports(session, principal, [item.asset for item in extracted])
        session.commit()
    except ConnectorPolicyDenied as exc:
        session.rollback()
        raise _connector_policy_error(exc) from exc
    except (FileStorageError, UnsafeFilePathError, ValueError) as exc:
        session.rollback()
        raise _http_error(exc) from exc
    finally:
        if zip_path:
            _cleanup_temp_file(zip_path)
    return FileUploadResponse(
        files=[
            _asset_response(session, item.asset, include_shares=True)
            for item in extracted
        ]
    )