syntax = "proto3";

package thumbnail_service;

option go_package = "./proto";

import "google/api/annotations.proto";

// Enum representing the supported file types for processing.
enum FileType {
    FILE_TYPE_UNSPECIFIED = 0;  // Default value when file type is not specified.
    IMAGE = 1;                  // Represents an image file type.
    VIDEO = 2;                  // Represents a video file type.
    PDF = 3;                    // Represents a PDF file type.
}

// Service providing thumbnail generation and OCR functionalities.
service ThumbnailService {
    // Generates a thumbnail image from a given file.
    // Accepts a ThumbnailRequest and returns a ThumbnailResponse.
    rpc GenerateThumbnail(ThumbnailRequest) returns (ThumbnailResponse) {
        option (google.api.http) = {
            post: "/v1/thumbnail"
            body: "*"
        };
    }

    // Performs OCR (Optical Character Recognition) on a provided file.
    // Accepts an OCRFileRequest and returns an OCRFileResponse.
    rpc OcrFile(OCRFileRequest) returns (OCRFileResponse) {
        option (google.api.http) = {
            post: "/v1/ocr"
            body: "*"
        };
    }
}

// Request message for thumbnail generation.
//
// The file_content must be a base64-encoded file (image, video, or PDF).
// Optional max_width and max_height can be provided to resize the thumbnail
// (values of 0 mean no resizing constraints).
message ThumbnailRequest {
    bytes file_content = 1;  // Base64-encoded bytes of the file to process.
    FileType file_type = 2;  // Specifies the type of the file.
    int32 max_width = 3;     // Maximum width of the generated thumbnail; 0 means no limit.
    int32 max_height = 4;    // Maximum height of the generated thumbnail; 0 means no limit.
}

// Response message for thumbnail generation.
//
// Contains a status message and the generated thumbnail as base64-encoded bytes.
message ThumbnailResponse {
    string message = 1;           // Status or informational message about the thumbnail generation.
    bytes thumbnail_content = 2;  // Base64-encoded bytes of the generated thumbnail image.
}

// Request message for OCR processing.
//
// The file_content must be a base64-encoded file.
// The cleanUp flag indicates if whitespace normalization and character cleanup
// should be applied to the extracted text.
message OCRFileRequest {
    bytes file_content = 1;  // Base64-encoded bytes of the file to OCR.
    FileType file_type = 2;  // Type of the file for future extensibility.
    bool cleanUp = 3;        // Whether to normalize whitespace and remove unnecessary characters.
}

// Response message for OCR processing.
//
// Contains a status message, the OCRed file content as bytes, and
// the extracted text content as a string.
message OCRFileResponse {
    string message = 1;         // Status message about the OCR operation.
    bytes ocr_content = 2;      // Base64-encoded bytes of the OCR processed file.
    string text_content = 3;    // Extracted text content from the file.
}