local log = require("log");
local json = require("json");
local notifier = require("notifier");

--- @class UpdaterEntry
--- @field url string
--- @field branch string
local _;

--- @class Updater
--- @field last_check integer
--- @field threshold integer in hours (mc time)
--- @field api_url string
--- @field curr_commit_hash string
--- @field updated_files table<string, UpdaterEntry> {path: {url, branch}}
local updater  = {};
updater.__index = updater;

function updater.new()
	local c = setmetatable({}, updater);
    c.last_check = os.time();
    c.threshold = ((20*60)/24/60/60) * 5;
    c.api_url = "https://git.mcorangehq.xyz/api/v1/repos/xomf/keypadOS";
    c.curr_commit_hash = "";
    c.updated_files = {};
    c.updated_files["startup.lua"] = {
        url = "https://git.mcorangehq.xyz/xomf/keypadOS/raw/branch/main/rtmc.lua",
        branch = "main"
    };
	return c
end

function updater:addEntry(path, branch, url)
    self.updated_files[path] = {
        branch = branch,
        url = url
    };
    self:update(path, url);
end

function updater:checkAndUpdateAll()
    local updated = false;
    for path, entry in pairs(self.updated_files) do
        log.debug("Checking update for " .. path);
        if self:check(entry.branch) then
            self:update(path, entry.url);
            updated = true;
        end
    end
    if updated then
        log.info("Rebooting!");
        sleep(3);
        os.reboot();
    end
end

function updater:check(branch)
    local curr = os.time();
    if not ((math.abs(curr - self.last_check) >= self.threshold) and (self.curr_commit_hash ~= "")) then
        -- log.debug("Not time for an update yet");
        return false;
    end
    self.last_check = curr;

    local req, rerr = http.get(self.api_url .. "/commits?sha="..branch);
    if not req then
        log.error("Updater:check: Could not send request: " .. rerr);
        return false;
    end

    local body, berr = req.readAll();
    if not req then
        log.error("Updater:check: Could not get body of request: " .. berr);
        return false;
    end

    local data = json.decode(body);
    if self.curr_commit_hash == "" then
        log.debug("No commit hash found, setting");
        self.curr_commit_hash = data[1].hash;
    elseif data[1].hash ~= self.curr_commit_hash then
        log.debug("Commit hash doesnt match, probbably an update");
        return true;
    end

    return false;
end

function updater:update(path, url)
    local req, rerr = http.get(url .. "?x=" .. tostring(math.random(0,69420)));
    if not req then
        log.error("Updater:update: Could not send request for update: " .. rerr);
        return;
    end

    local body, berr = req.readAll();
    if not body then
        log.error("Updater:update: Could not get file for update: " .. berr);
        return;
    end

    if fs.exists(path .. ".bak") then
        fs.delete(path .. ".bak");
    end
    if fs.exists(path) then
        fs.copy(path, path..".bak");
        fs.delete(path);
    end

    local fd = fs.open(path, "w");
    fd.write(body);
    fd.close();

    local notif = "Computer #" .. tostring( os.getComputerID() ) .. " updating";
    notifier.notify("default", notif);
    log.debug("New update written to disk (" .. path .. ")");
end


return updater;