/*
    * DataTransfer.hpp
    * Multi-format payloads shared by the clipboard and drag and drop
    * Copyright (c) 2026 Daniel Hammer
*/

#pragma once
#include <cstdint>
#include "Syscall.hpp"

// A transfer is a small set of formats, each one MIME type plus bytes, all
// owned by the kernel heap. Producers offer every representation they can
// (a file list and its paths as text, say) and each consumer reads the one it
// understands. The clipboard holds one transfer per user; the window server
// holds the active drag's.
namespace DataTransfer {

    struct Format {
        char     mime[montauk::abi::TRANSFER_MIME_MAX];
        uint8_t* data;
        uint32_t len;
    };

    struct Transfer {
        Format   formats[montauk::abi::TRANSFER_MAX_FORMATS];
        uint32_t count;
    };

    // Copy `count` formats in from user memory, validating every pointer the
    // items carry (the item array itself must already be validated). On
    // failure `out` is left empty. Returns a StatusCodes value.
    int BuildFromUser(const montauk::abi::TransferItem* items, uint32_t count, Transfer& out);

    // A transfer holding just `text` as TRANSFER_MIME_TEXT.
    int BuildText(const char* text, uint32_t len, Transfer& out);

    void Free(Transfer& transfer);

    // Exact match first; a request without parameters ("text/plain") also
    // matches a stored format that has them ("text/plain;charset=utf-8").
    const Format* Find(const Transfer& transfer, const char* mime);

    uint32_t ListFormats(const Transfer& transfer, montauk::abi::TransferFormatInfo* out, uint32_t max);

    // Copy a format to a (validated) user buffer. *outLen always receives the
    // full length; BufferTooSmall when it does not fit, nothing copied then.
    int CopyOut(const Format& format, void* buffer, uint32_t bufferLen, uint32_t* outLen);

    // MIME string checks shared by every entry point: "type/subtype" with
    // optional parameters, printable ASCII, shorter than TRANSFER_MIME_MAX.
    bool ValidMime(const char* mime);
}