"""
    tools/image.jl - Image utilities

This module provides image detection and encoding utilities.
"""

module Image

using ..Types: *

function detectSupportedImageMimeType(buffer::Vector{UInt8})::Union{String, Nothing}
    if length(buffer) >= 3 && buffer[1:3] == [0xff, 0xd8, 0xff]
        if buffer[4] == 0xf7
            return nothing
        end
        return "image/jpeg"
    end

    if length(buffer) >= 8 && buffer[1:8] == [0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]
        return "image/png"
    end

    if length(buffer) >= 3 && buffer[1:3] == [0x47, 0x49, 0x46]
        return "image/gif"
    end

    if length(buffer) >= 12 && buffer[1:4] == [0x52, 0x49, 0x46, 0x46] && buffer[9:12] == [0x57, 0x45, 0x42, 0x50]
        return "image/webp"
    end

    if length(buffer) >= 2 && buffer[1:2] == [0x42, 0x4d]
        return "image/bmp"
    end

    return nothing
end

function encodeBase64(bytes::Vector{UInt8})::String
    alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
    output = ""

    for i in 1:3:length(bytes)
        first_byte = i <= length(bytes) ? bytes[i] : 0
        second_byte = i+1 <= length(bytes) ? bytes[i+1] : 0
        third_byte = i+2 <= length(bytes) ? bytes[i+2] : 0

        output *= alphabet[first_byte >> 2 + 1]
        output *= alphabet[(((first_byte & 0x03) << 4) | ((second_byte >> 4) & 0x0f)) + 1]
        
        if i+1 <= length(bytes)
            output *= alphabet[(((second_byte & 0x0f) << 2) | ((third_byte >> 6) & 0x03)) + 1]
        else
            output *= "="
        end

        if i+2 <= length(bytes)
            output *= alphabet[third_byte & 0x3f + 1]
        else
            output *= "="
        end
    end

    return output
end

end