-- Initialise global variables related to booting.
_G._KERNEL_ROOT = "/"
_G._KERNEL_LOCS = {}
_G._BOOT_DEFAULT = nil
_G._PELICAN_DEBUG = false
_G._PELICAN_VERSION = "0.1.0"
_G._PELICAN_CONFIG_LOCATION = ""

print("Pelican " .. _G._PELICAN_VERSION)
print("Searching for Pelican configuration.")
local directories = {}
directories[1] = "/"
local x = 2
local s = 1
local v = true
while v and _G._PELICAN_CONFIG_LOCATION == "" do
    local files = fs.list(directories[s])
    for i = 1, #files do
        if fs.isDir(fs.combine(directories[s], files[i])) then
            table.insert(directories, x, directories[s] .. files[i])
            x = x + 1
        elseif fs.getName(fs.combine(directories[s], files[i])) == "pelican.conf.lua" then
            _G._PELICAN_CONFIG_LOCATION = fs.combine(directories[s], files[i])
        end
    end
    table.remove(directories, s)
    s = s + 1
    if directories[s] == nil then
        v = false
    end
end

if _G._PELICAN_CONFIG_LOCATION ~= "" then
    print("Found config at " .. _G._PELICAN_CONFIG_LOCATION .. ".")
    dofile(_G._PELICAN_CONFIG_LOCATION)
    print("Config applied!")
else
    print("No config found.")
    if not _G._PELICAN_DEBUG then
        term.clear()
        term.setCursorPos(1, 1)
    end
end

if #_G._KERNEL_LOCS ~= 0 and _G._BOOT_DEFAULT == nil then
    print("")
    if not _G._PELICAN_DEBUG then
        term.clear()
        term.setCursorPos(1, 1)
    end
    print("These kernels are available to boot to: ")
    for i = 1, #_G._KERNEL_LOCS do
        print(i.. ". " .. _G._KERNEL_LOCS[i])
    end
    print("To boot one of these kernels, type boot followed by the index number.")
    print("Just type boot to boot kernel #1.")
    print("")
end

local boot = false

if _G._BOOT_DEFAULT ~= nil and _G._KERNEL_LOCS[_G._BOOT_DEFAULT] ~= nil then
    boot = _G._KERNEL_LOCS[_G._BOOT_DEFAULT]
end

if not boot then    
    print("No default kernel set. Dropping to shell.")

    while not boot do
        write("> ")
        local cmd = read()
        if cmd == "restart" or cmd == "reboot" then
            os.reboot()
        elseif cmd:find("^boot") and cmd ~= "boot" then
            cmd = cmd:gsub("boot ", "")
            if _G._KERNEL_LOCS[tonumber(cmd)] then
                boot = _G._KERNEL_LOCS[tonumber(cmd)]
            elseif fs.exists(cmd) then
                boot = cmd
            else
                print("Please enter a valid kernel index number or kernel path.")
            end
        elseif cmd == "boot" then
            if _G._KERNEL_LOCS[1] then
                boot = _G._KERNEL_LOCS[1]
            else
                print("Please enter a kernel path.")
            end
        elseif cmd == "shutdown" or cmd == "poweroff" or cmd == "halt" then
            os.shutdown()
        elseif cmd == "help" then
            print("shutdown - halts execution")
            print("boot - executes a kernel")
            print("restart - restarts computer")
            print("help - prints help information")
            print("version - prints version information")
        elseif cmd == "version" then
            print("Pelican boot loader version " .. _G._PELICAN_VERSION)
            print("This software is licensed under the GNU General Public License.")
            print("More information about this software can be found online at:")
            print("https://git.colean.cc/canaryos/pelican")
        end
    end
end

dofile(boot)