#!/bin/lua

--[[ Copyright (c) 2026 Alexander Hill

Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE. ]]

local liquid = require("liquid")
local posix = require("posix")
local tinytoml = require("tinytoml")

local config
local config_path = "/etc/maple.toml"
local sysroot = "/"
local templates = "/usr/share/mapleconf"

local function render_directory(stack)
    local path
    if #stack == 0 then
        path = "/"
    else
        path = "/" .. table.concat(stack, "/") .. "/"
    end

    local files = posix.dir(templates .. path)
    for _, entry in ipairs(files) do
        if not string.match(entry, "^%.+$") then
            local fullpath = path .. entry

            local stat = posix.stat(templates .. fullpath)
            if stat.type == "directory" then
                if not posix.access(sysroot .. fullpath) then
                    posix.mkdir(sysroot .. fullpath)
                end

                local newstack = {}
                -- Why does Lua lack the ability to copy tables? ~ahill
                for _, v in ipairs(stack) do
                    table.insert(newstack, v)
                end
                table.insert(newstack, entry)
                render_directory(newstack)

            elseif stat.type == "regular" then
                print("Updating " .. fullpath)

                local template = io.open(templates .. fullpath, "r")
                if template then
                    local target = io.open(sysroot .. fullpath, "w")
                    if target then
                        local context = liquid.InterpreterContext:new(config)
                        local engine = liquid.Template:parse(template:read("*all"))
                        target:write(engine:render(context))
                        target:close()
                    end
                    template:close()
                end

            else
                print("BUG: Directory entry type " .. stat.type .. " not recognized.")
            end
        end
    end
end

-- ENTRY POINT

for opt, optarg, optind in posix.unistd.getopt(arg, "c:hr:t:") do
    if opt == "c" then
        config_path = optarg
    elseif opt == "h" then
        -- Pardon the formatting. This should be cleaned up later. ~ahill
        print[[Usage: mapleconf [option [option ...] ]
    -c <file> - Sets the file to source configuration data from
    -h        - Displays this help message
    -r <path> - Sets the sysroot to configure
    -t <path> - Sets the path of the template directory]]
        os.exit(1)
    elseif opt == "r" then
        sysroot = optarg
    elseif opt == "t" then
        templates = optarg
    else
        print("Unknown option: " .. arg[optind - 1])
        os.exit(1)
    end
end

config = tinytoml.parse(config_path)

render_directory{}