ampache-common.lua

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-- ----------------------------------------------- --
----     Luci4 utils for Ampache API calls      -----
-- -------- https://github.com/icefields --------- --
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function shouldPrintHelp()
    -- Check for the help flag (-h)
    if arg[1] == "-h" then
        return true
    end

    -- Ensure that the server_url, username, and password are provided
    if not arg[1] or not arg[2] or not arg[3] then
        print("Error: Missing required arguments (server_url, username, password). Use -h for help.")
        return true
    end
    return false
end

function parseArgs(arg)
    local limit = 100  -- Default limit
    local isJsonOutput = false
    local typeValue = ""  -- Default filter
    local filterValue = ""  -- Default filter
    local isPrintUrl = false
    local include = nil
    
    local serverUrl = arg[1]
    local username = arg[2]
    local password = arg[3]

    -- Parse the command-line arguments
    for i = 4, #arg do
        local arg_val = arg[i]
        if arg_val == "-l" then
            -- Limit argument
            limit = tonumber(arg[i + 1]) or 100
            i = i + 1  -- Skip the next argument
        elseif arg_val == "-f" then
            -- Filter argument
            filterValue = arg[i + 1] or ""
            i = i + 1  -- Skip the next argument
        elseif arg_val == "-t" then
            -- Filter argument
            typeValue = arg[i + 1] or ""
            i = i + 1  -- Skip the next argument
        elseif arg_val == "-i" then
            include = arg[i + 1]
            i = i + 1
        elseif arg_val == "-j" then
	        isJsonOutput = true
        elseif arg_val == "-d" then
	        isPrintUrl = true
        end
    end

    return serverUrl, username, password, limit, filterValue, isJsonOutput, isPrintUrl, include, typeValue
end

-- Print the help guide
local function printHelp(name)
    print("Usage: lua " .. name .. 
[[ <server_url> <username> <password> [OPTIONS]

Required arguments:
  <server_url>   The URL of the Ampache server
  <username>     The username for authentication
  <password>     The password for authentication

Optional arguments:
  -l <limit>     Limit the number of items to retrieve (default: 100)
  -f <filter>    Specify the filter for the items
  -j		     Prints the original json from the network response, when this is passed, all other optional args are ignored
  -t             Type
  -h             Show this help message
  -d             Print the request url, useful for debugging
]])
end

-- Function to check if a value is valid (not nil, empty, or 'null')
local function isValid(value)
    return value ~= nil and value ~= '' and value ~= 'null' and tostring(value) ~= 'userdata: (nil)'
end

local function format_value(v)
    if type(v) == "number" and v % 1 == 0 then
        return string.format("%d", v)  -- remove .0
    else
        return tostring(v)  -- fallback
    end
end

-- Function to print only if valid
local function safePrint(label, value)
    if isValid(value) then
        print(string.format("%s %s", label, format_value(value)))
    end
end

function urlencode(str)
    return (str:gsub("([^%w%-%.%_~])", function(c)
        return string.format("%%%02X", string.byte(c))  -- Replace each non-URL-safe character with its encoded form
    end))
end

function fileExists(path)
    local f = io.open(path, "r")
    if f then
        f:close()
        return true
    else
        return false
    end
end

local function isFileEmpty(path)
    local f = io.open(path, "r")
    if not f then return true end  -- file doesn't exist
    local size = f:seek("end")
    f:close()
    return size == 0
end

local function readFile(path)
    local f = io.open(path, "r")
    if not f then return nil end
    local content = f:read("*a")  -- read entire file
    f:close()
    return content
end

local function writeFile(path, string)
    local file = io.open(path, "w")
    file:write(string)
    file:close()
end

return {
    format_value = format_value,
    isValid = isValid,
    safePrint = safePrint,
    urlencode = urlencode,
    printHelp = printHelp,
    shouldPrintHelp = shouldPrintHelp,
    parseArgs = parseArgs,
    fileExists = fileExists,
    isFileEmpty = isFileEmpty,
    readFile = readFile,
    writeFile = writeFile
}