local lib = {}
local appregloc = ".appreg"
local expect = require "cc.expect".expect
local file = fs.open("/repos.dat","r")
local repos = {}
if file then
    repos = textutils.unserialise(file.readAll() or "") or repos
end
local function saveRepos()
    local file = fs.open("/repos.dat","w")
    file.write(textutils.serialise(repos))
    file.close()
end
function lib.addRepo(id)
    expect(1,id,"number")
    repos[id] = "computer"
    saveRepos()
end
function lib.getRepos()
    return repos
end
function lib.rmRepo(id)
    expect(1,id,"number")
    repos[id] = nil
    saveRepos()
end
function lib.listPackages(type)
    local queued_requests = {}
    local recorded_packages = {}
    for k,v in pairs(repos) do
        if v == "computer" then
            network.send({proto="query",package_type=type},k)
            queued_requests[k] = "computer"
        end 
    end
    local next_timestamp = os.clock()+5
    repeat
        local event = {os.pullEvent()}
        if event[1] == "network_packet" then
            if queued_requests[event[3]] == "computer" and event[2].proto == "query_resp" and event[2].package_type == type then
                for name,data in pairs(event[2].data) do
                    if recorded_packages[name] then
                        recorded_packages[name].repos[event[3]] = event[4]
                    else
                        data.repos = {[event[3]] = event[4]}
                        recorded_packages[name] = data
                    end
                end
                queued_requests[event[3]] = nil
            end
        end
    until next(queued_requests) == nil or os.clock() >= next_timestamp
    return recorded_packages
end

function lib.getPackageData(type,id)
    print(type,id)
    local queued_requests = {}
    local package = nil
    for k,v in pairs(repos) do
        if v == "computer" then
            network.send({proto="get_data",package_type=type,id=id},k)
            queued_requests[k] = "computer"
        end 
    end
    local next_timestamp = os.clock()+5
    repeat
        local event = {os.pullEvent()}
        if event[1] == "network_packet" then
            if queued_requests[event[3]] == "computer" and event[2].proto == "data_resp" and event[2].package_type == type then
                if package == nil then
                    package = event[2].data
                    package.repos = {[event[3]] = event[4]}
                end
                package.repos[event[3]] = event[4]
                queued_requests[event[3]] = nil
            end
        end
    until next(queued_requests) == nil or os.clock() >= next_timestamp
    return package
end

local function add_app_to_reg(appid)
    local file = fs.open(appregloc,"r")
    local data = {}
    if file then data = textutils.unserialise(file.readAll() or "") or {} file.close() end
    data[appid] = true
    local file = fs.open(appregloc,"w")
    if file then
        file.write(textutils.serialise(data))
        file.close()
    end
end

function lib.appInstalled(appid)
    local file = fs.open(appregloc,"r")
    local data = {}
    if file then data = textutils.unserialise(file.readAll() or "") or {} file.close() end
    return data[appid] or false
end

local function remove_app_from_reg(appid)
    local file = fs.open(appregloc,"r")
    local data = {}
    if file then data = textutils.unserialise(file.readAll() or "") or {} file.close() end
    data[appid] = nil
    local file = fs.open(appregloc,"w")
    if file then
        file.write(textutils.serialise(data))
        file.close()
    end
end

local function install_app_from_data(data)
    if not data.meta or not data.package or not data.meta.appid then return false, "incorrect package format" end
    add_app_to_reg(data.meta.appid)
    local app_meta = fs.open(fs.combine("/apps-meta",data.meta.appid..".meta"),"w")
    local app = fs.open(fs.combine("/apps",data.meta.appid),"w")
    if app_meta and app then
        app_meta.write(textutils.serialise(data.meta))
        app.write(data.package)
        app_meta.close()
        app.close()
        return true
    end
    return false, "failed to open file"
end
function lib.uninstallApp(id)
    if lib.appInsalled(id) then
        remove_app_from_reg(id)
        fs.delete(fs.combine("/apps-meta",id..".meta"))
        fs.delete(fs.combine("/appears",id))
        return true
    end
    return false, "Not installed"
end
function lib.installApp(package)
    if type(package) == "table" then
        return install_app_from_data(package)
    elseif type(package) == "string" then
        local handle = nil
        if http.checkURL(package) then
            handle = http.get(package)
        else
            handle = fs.open(package,"r")
        end
        if handle then
            local data = textutils.unserialise(handle.readAll() or "")
            if data then
                return install_app_from_data(data)
            end
            handle.close()
        end
    end
    return false
end

_G.repo = lib