// Copyright 2026 Arctel.net
// SPDX-License-Identifier: Apache-2.0

package contracts

import (
	"context"
	"database/sql/driver"
	"encoding/json"
	"fmt"
	"io"
	"time"
)

// UploadMetadataDTO represents upload metadata JSON.
type UploadMetadataDTO struct {
	Width        int            `json:"width,omitempty"`
	Height       int            `json:"height,omitempty"`
	Duration     float64        `json:"duration,omitempty"`
	OriginalMime string         `json:"original_mime,omitempty"`
	UserAgent    string         `json:"user_agent,omitempty"`
	ClientIP     string         `json:"client_ip,omitempty"`
	Bucket       string         `json:"bucket,omitempty"`
	Extra        map[string]any `json:"extra,omitempty"`
}

// Value implements the driver.Valuer interface for database serialization.
func (m UploadMetadataDTO) Value() (driver.Value, error) {
	return json.Marshal(m)
}

// Scan implements the sql.Scanner interface for database deserialization.
func (m *UploadMetadataDTO) Scan(value any) error {
	if value == nil {
		*m = UploadMetadataDTO{}
		return nil
	}
	switch v := value.(type) {
	case []byte:
		return json.Unmarshal(v, m)
	case string:
		return json.Unmarshal([]byte(v), m)
	default:
		return fmt.Errorf("cannot scan type %T into UploadMetadataDTO", value)
	}
}

// UploadDTO represents an uploaded file record.
type UploadDTO struct {
	ID        uint64            `json:"id"`
	UserID    uint64            `json:"user_id"`
	FileName  string            `json:"file_name"`
	FilePath  string            `json:"file_path"`
	MimeType  string            `json:"mime_type"`
	Size      int64             `json:"size"`
	Hash      string            `json:"hash"`
	Status    string            `json:"status"`
	Type      string            `json:"type"`
	Metadata  UploadMetadataDTO `json:"metadata"`
	CreatedAt time.Time         `json:"created_at"`
	UpdatedAt time.Time         `json:"updated_at"`
}

// OpenedUploadDTO encapsulates the retrieved object stream and its metadata.
type OpenedUploadDTO struct {
	Upload        UploadDTO
	Body          io.ReadCloser
	ContentType   string
	ContentLength int64
}

// UploadService defines the unified contract for managed file uploads and media entities.
type UploadService interface {
	GetByID(ctx context.Context, id uint64) (*UploadDTO, error)
	OpenStoredUpload(ctx context.Context, id uint64) (*OpenedUploadDTO, error)
	Remove(ctx context.Context, id uint64) error
	RemoveOwned(ctx context.Context, id uint64, userID uint64) error
	FindByHash(ctx context.Context, hash string, size int64) (*UploadDTO, error)
	RebuildStats(ctx context.Context) error
}