Imageconvert

-- CC:Tweaked Image Downloader & Converter
-- Downloads images from URLs and converts to displayable format
-- Works entirely within CC:Tweaked!

local args = {...}

-- CC:Tweaked color palette
local palette = {
    {240, 240, 240, "0"}, -- white
    {242, 178, 51, "1"},  -- orange
    {229, 127, 216, "2"}, -- magenta
    {153, 178, 242, "3"}, -- lightBlue
    {222, 222, 108, "4"}, -- yellow
    {127, 204, 25, "5"},  -- lime
    {242, 178, 204, "6"}, -- pink
    {76, 76, 76, "7"},    -- gray
    {153, 153, 153, "8"}, -- lightGray
    {76, 153, 178, "9"},  -- cyan
    {178, 102, 229, "a"}, -- purple
    {51, 102, 204, "b"},  -- blue
    {127, 102, 76, "c"},  -- brown
    {87, 166, 78, "d"},   -- green
    {204, 76, 76, "e"},   -- red
    {25, 25, 25, "f"},    -- black
}

-- Find closest color
local function findClosest(r, g, b)
    local minDist = math.huge
    local closest = "f"
    for _, c in ipairs(palette) do
        local dr = r - c[1]
        local dg = g - c[2]
        local db = b - c[3]
        local dist = dr*dr + dg*dg + db*db
        if dist < minDist then
            minDist = dist
            closest = c[4]
        end
    end
    return closest
end

-- Parse PPM P3 (ASCII) format
local function parsePPM(data)
    local lines = {}
    for line in data:gmatch("[^\n]+") do
        if not line:match("^#") then
            table.insert(lines, line)
        end
    end

    local format = lines[1]
    if format ~= "P3" then
        return nil, "Not P3 PPM format"
    end

    local dims = lines[2]:match("(%d+)%s+(%d+)")
    local width, height = tonumber(lines[2]:match("^(%d+)")), tonumber(lines[2]:match("%s(%d+)"))
    if not width or not height then
        return nil, "Invalid dimensions"
    end

    local maxVal = tonumber(lines[3])
    if not maxVal then
        return nil, "Invalid max value"
    end

    -- Collect all pixel values
    local values = {}
    for i = 4, #lines do
        for num in lines[i]:gmatch("%d+") do
            table.insert(values, tonumber(num))
        end
    end

    -- Build pixel array
    local pixels = {}
    local idx = 1
    for y = 1, height do
        pixels[y] = {}
        for x = 1, width do
            local r = values[idx] or 0
            local g = values[idx + 1] or 0
            local b = values[idx + 2] or 0
            -- Scale to 0-255 if needed
            if maxVal ~= 255 then
                r = math.floor(r * 255 / maxVal)
                g = math.floor(g * 255 / maxVal)
                b = math.floor(b * 255 / maxVal)
            end
            pixels[y][x] = findClosest(r, g, b)
            idx = idx + 3
        end
    end

    return {width = width, height = height, pixels = pixels}
end

-- Parse simple BMP (24-bit uncompressed)
local function parseBMP(data)
    local function readInt(str, pos, bytes)
        local val = 0
        for i = 0, bytes - 1 do
            val = val + (str:byte(pos + i) or 0) * (256 ^ i)
        end
        return val
    end

    -- Check BMP signature
    if data:sub(1, 2) ~= "BM" then
        return nil, "Not a BMP file"
    end

    local dataOffset = readInt(data, 11, 4)
    local width = readInt(data, 19, 4)
    local height = readInt(data, 23, 4)
    local bpp = readInt(data, 29, 2)
    local compression = readInt(data, 31, 4)

    if bpp ~= 24 or compression ~= 0 then
        return nil, "Only 24-bit uncompressed BMP supported"
    end

    local rowSize = math.floor((bpp * width + 31) / 32) * 4

    local pixels = {}
    for y = 1, height do
        pixels[y] = {}
        local rowStart = dataOffset + (height - y) * rowSize
        for x = 1, width do
            local pixelStart = rowStart + (x - 1) * 3
            local b = data:byte(pixelStart + 1) or 0
            local g = data:byte(pixelStart + 2) or 0
            local r = data:byte(pixelStart + 3) or 0
            pixels[y][x] = findClosest(r, g, b)
        end
    end

    return {width = width, height = height, pixels = pixels}
end

-- Resize image
local function resizeImage(img, newWidth, newHeight)
    if not img or not img.pixels or not img.width or not img.height then
        return nil, "Invalid image data"
    end

    local resized = {width = newWidth, height = newHeight, pixels = {}}
    local xRatio = img.width / newWidth
    local yRatio = img.height / newHeight

    for y = 1, newHeight do
        resized.pixels[y] = {}
        for x = 1, newWidth do
            local srcX = math.floor((x - 0.5) * xRatio) + 1
            local srcY = math.floor((y - 0.5) * yRatio) + 1
            srcX = math.max(1, math.min(img.width, srcX))
            srcY = math.max(1, math.min(img.height, srcY))
            -- Safe access with fallback
            local row = img.pixels[srcY]
            if row then
                resized.pixels[y][x] = row[srcX] or "f"
            else
                resized.pixels[y][x] = "f"
            end
        end
    end

    return resized
end

-- Save as NFP
local function saveNFP(img, filename)
    local file = fs.open(filename, "w")
    if not file then
        return false, "Cannot create file"
    end

    for y = 1, img.height do
        local line = ""
        for x = 1, img.width do
            line = line .. (img.pixels[y][x] or "f")
        end
        file.writeLine(line)
    end
    file.close()
    return true
end

-- Load NFP file
local function loadNFP(filename)
    if not fs.exists(filename) then
        return nil, "File not found"
    end

    local file = fs.open(filename, "r")
    if not file then
        return nil, "Cannot open file"
    end

    local pixels = {}
    local width = 0
    local y = 1

    while true do
        local line = file.readLine()
        if not line then break end
        pixels[y] = {}
        width = math.max(width, #line)
        for x = 1, #line do
            pixels[y][x] = line:sub(x, x)
        end
        y = y + 1
    end
    file.close()

    return {width = width, height = y - 1, pixels = pixels}
end

-- Color mapping for display
local colorMap = {
    ["0"] = colors.white,
    ["1"] = colors.orange,
    ["2"] = colors.magenta,
    ["3"] = colors.lightBlue,
    ["4"] = colors.yellow,
    ["5"] = colors.lime,
    ["6"] = colors.pink,
    ["7"] = colors.gray,
    ["8"] = colors.lightGray,
    ["9"] = colors.cyan,
    ["a"] = colors.purple,
    ["b"] = colors.blue,
    ["c"] = colors.brown,
    ["d"] = colors.green,
    ["e"] = colors.red,
    ["f"] = colors.black,
}

-- Display image
local function displayImage(img, offsetX, offsetY)
    offsetX = offsetX or 0
    offsetY = offsetY or 0

    for y = 1, img.height do
        for x = 1, img.width do
            local char = img.pixels[y][x]
            local color = colorMap[char:lower()] or colors.black
            term.setCursorPos(x + offsetX, y + offsetY)
            term.setBackgroundColor(color)
            term.write(" ")
        end
    end
end

-- Download and convert from URL
local function downloadImage(url, filename, targetWidth, targetHeight)
    print("Downloading image...")

    local response, err = http.get(url, nil, true) -- binary mode
    if not response then
        return nil, "Download failed: " .. (err or "unknown error")
    end

    local data = response.readAll()
    response.close()

    print("Downloaded " .. #data .. " bytes")

    -- Try to detect format
    local img, parseErr

    if data:sub(1, 2) == "P3" then
        print("Detected PPM format")
        img, parseErr = parsePPM(data)
    elseif data:sub(1, 2) == "BM" then
        print("Detected BMP format")
        img, parseErr = parseBMP(data)
    else
        return nil, "Unsupported format. Use PPM (P3) or BMP (24-bit)"
    end

    if not img then
        return nil, "Parse error: " .. (parseErr or "unknown")
    end

    print("Image size: " .. img.width .. "x" .. img.height)

    -- Resize if needed
    if targetWidth and targetHeight then
        print("Resizing to " .. targetWidth .. "x" .. targetHeight)
        local resized, resizeErr = resizeImage(img, targetWidth, targetHeight)
        if not resized then
            return nil, "Resize error: " .. (resizeErr or "unknown")
        end
        img = resized
    end

    -- Save
    if filename then
        local ok, saveErr = saveNFP(img, filename)
        if ok then
            print("Saved to: " .. filename)
        else
            print("Save error: " .. saveErr)
        end
    end

    return img
end

-- Interactive menu
local function showMenu()
    local w, h = term.getSize()

    while true do
        term.setBackgroundColor(colors.black)
        term.setTextColor(colors.white)
        term.clear()
        term.setCursorPos(1, 1)

        term.setTextColor(colors.yellow)
        print("=== CC Image Converter ===")
        term.setTextColor(colors.white)
        print("")
        print("1. Download from URL")
        print("2. View saved image")
        print("3. List saved images")
        print("4. Convert URL to file")
        print("5. Help")
        print("6. Exit")
        print("")
        term.setTextColor(colors.gray)
        print("Supports: PPM (P3), BMP (24-bit)")
        term.setTextColor(colors.white)
        print("")
        write("Choice: ")

        local choice = read()

        if choice == "1" then
            -- Download and display
            print("")
            write("Enter image URL: ")
            local url = read()
            if url and #url > 0 then
                local img, err = downloadImage(url, nil, w, h - 1)
                if img then
                    term.clear()
                    displayImage(img, 0, 0)
                    term.setCursorPos(1, h)
                    term.setBackgroundColor(colors.gray)
                    term.setTextColor(colors.white)
                    term.write(" Press any key ")
                    os.pullEvent("key")
                else
                    print("Error: " .. err)
                    print("Press any key...")
                    os.pullEvent("key")
                end
            end

        elseif choice == "2" then
            -- View saved image
            print("")
            write("Filename (.nfp): ")
            local filename = read()
            if filename and #filename > 0 then
                if not filename:match("%.nfp$") then
                    filename = filename .. ".nfp"
                end
                local img, err = loadNFP(filename)
                if img then
                    term.clear()
                    displayImage(img, 0, 0)
                    term.setCursorPos(1, h)
                    term.setBackgroundColor(colors.gray)
                    term.setTextColor(colors.white)
                    term.write(" Press any key ")
                    os.pullEvent("key")
                else
                    print("Error: " .. err)
                    print("Press any key...")
                    os.pullEvent("key")
                end
            end

        elseif choice == "3" then
            -- List images
            print("")
            print("Saved images:")
            local files = fs.list("/")
            local found = false
            for _, f in ipairs(files) do
                if f:match("%.nfp$") then
                    print("  " .. f)
                    found = true
                end
            end
            -- Check os/images folder too
            if fs.exists("os/images") then
                local osFiles = fs.list("os/images")
                for _, f in ipairs(osFiles) do
                    if f:match("%.nfp$") then
                        print("  os/images/" .. f)
                        found = true
                    end
                end
            end
            if not found then
                print("  (no images found)")
            end
            print("")
            print("Press any key...")
            os.pullEvent("key")

        elseif choice == "4" then
            -- Download and save
            print("")
            write("Enter image URL: ")
            local url = read()
            if url and #url > 0 then
                write("Save as (without .nfp): ")
                local filename = read()
                if filename and #filename > 0 then
                    filename = filename .. ".nfp"
                    write("Width (default " .. w .. "): ")
                    local tw = tonumber(read()) or w
                    write("Height (default " .. (h-1) .. "): ")
                    local th = tonumber(read()) or (h - 1)

                    local img, err = downloadImage(url, filename, tw, th)
                    if not img then
                        print("Error: " .. err)
                    end
                    print("")
                    print("Press any key...")
                    os.pullEvent("key")
                end
            end

        elseif choice == "5" then
            -- Help
            term.clear()
            term.setCursorPos(1, 1)
            term.setTextColor(colors.yellow)
            print("=== Help ===")
            term.setTextColor(colors.white)
            print("")
            print("This program downloads images from")
            print("the internet and displays them on")
            print("your CC:Tweaked computer.")
            print("")
            term.setTextColor(colors.lime)
            print("Supported formats:")
            term.setTextColor(colors.white)
            print("- PPM P3 (ASCII)")
            print("- BMP 24-bit uncompressed")
            print("")
            term.setTextColor(colors.lime)
            print("To convert images:")
            term.setTextColor(colors.white)
            print("1. Use online converter to make")
            print("   PPM or BMP from your PNG/JPG")
            print("2. Upload somewhere (pastebin, etc)")
            print("3. Use URL to download here")
            print("")
            term.setTextColor(colors.lime)
            print("Online converters:")
            term.setTextColor(colors.cyan)
            print("convertio.co, online-convert.com")
            print("")
            term.setTextColor(colors.white)
            print("Press any key...")
            os.pullEvent("key")

        elseif choice == "6" then
            term.clear()
            term.setCursorPos(1, 1)
            return
        end
    end
end

-- Command line usage
if #args == 0 then
    showMenu()
elseif args[1] == "view" and args[2] then
    local filename = args[2]
    if not filename:match("%.nfp$") then
        filename = filename .. ".nfp"
    end
    local img, err = loadNFP(filename)
    if img then
        term.clear()
        displayImage(img, 0, 0)
        local w, h = term.getSize()
        term.setCursorPos(1, h)
        term.setBackgroundColor(colors.gray)
        term.write(" Press any key ")
        os.pullEvent("key")
        term.setBackgroundColor(colors.black)
        term.clear()
        term.setCursorPos(1, 1)
    else
        print("Error: " .. err)
    end
elseif args[1] == "get" and args[2] then
    local url = args[2]
    local filename = args[3]
    local tw = tonumber(args[4]) or 51
    local th = tonumber(args[5]) or 19
    local img, err = downloadImage(url, filename, tw, th)
    if not img then
        print("Error: " .. err)
    end
elseif args[1] == "help" then
    print("CC Image Converter")
    print("")
    print("Usage:")
    print("  imgconv           - Interactive menu")
    print("  imgconv view FILE - View saved image")
    print("  imgconv get URL [FILE] [W] [H]")
    print("                    - Download & convert")
    print("  imgconv help      - Show this help")
    print("")
    print("Formats: PPM (P3), BMP (24-bit)")
else
    print("Unknown command. Use 'imgconv help'")
end