keyringmgr = {
    keyring = nil
}

local function get_keyring_path()
    return core.get_user_path() .. DIR_DELIM .. "client" .. DIR_DELIM .. core.settings:get("keyring_file")
end

local function save_keyring(keyring)
    core.safe_file_write(get_keyring_path(), core.write_json(keyring))
end

local function read_keyring()
    local path = get_keyring_path()

    local file = io.open(path, "r")
    if file then
        local json = file:read("*all")
        file:close()
        return core.parse_json(json)
    end
end

local function is_for_server(keys, address, port)
    return keys.address == address and keys.port == port
end

local function delete_keys(keyring, address, port)
    for i = 1, #keyring do
        local keys = keyring[i]

        if is_for_server(keys, address, port) then
            table.remove(keyring, i)
            return
        end
    end
end

local function get_keys(keyring, address, port)
    for i = 1, #keyring do
        local keys = keyring[i]

        if is_for_server(keys, address, port) then
            return keys
        end
    end
    -- If we don't find any existing keys, we make a blank set for the server
    local keys = {
        address = address,
        port = port,
        logins = {},
        last_login = false
    }
    table.insert(keyring, 1, keys)
    save_keyring(keyring)
    return keys
end

local function rewrite_keys(keyring, address, port, new_keys)
    delete_keys(keyring, address, port)
    table.insert(keyring, 1, new_keys)
    save_keyring(keyring)
end

function keyringmgr.get_keyring()
    if keyringmgr.keyring then
        return keyringmgr.keyring
    end

    keyringmgr.keyring = {}

    -- Add keyring, removing duplicates
    local seen = {}
    for _, keys in ipairs(read_keyring() or {}) do
        local key = ("%s:%d"):format(keys.address:lower(), keys.port)
        if not seen[key] then
            seen[key] = true
            keyringmgr.keyring[#keyringmgr.keyring + 1] = keys
        end
    end

    return keyringmgr.keyring
end

function keyringmgr.set_last_login(address, port, playername)
    local keyring = keyringmgr.get_keyring()
    local new_keys = get_keys(keyring, address, port)
    new_keys.last_login = playername

    rewrite_keys(keyring, address, port, new_keys)
end

function keyringmgr.set_login(address, port, playername, password)
    -- If the user doesn't want to remember logins, we completely skip the process
    if not core.settings:get_bool("remember_login") then
        return
    end
    assert(type(port) == "number")

    local keyring = keyringmgr.get_keyring()
    local new_keys = get_keys(keyring, address, port);

    -- Check for existing entires for playername
    for _, login in ipairs(new_keys.logins or {}) do
        if login.playername and login.playername == playername then
            login.password = password
            break
        end
    end

    -- If not, we add a new key
    if not new_keys.logins then
        new_keys.logins = {}
    end
    table.insert(new_keys.logins, 1, {
        playername = playername,
        password = password
    })

    keyringmgr.set_last_login(address, port, playername)

    rewrite_keys(keyring, address, port, new_keys)
end

function keyringmgr.get_login(address, port, playername)
    assert(type(port) == "number")

    local keyring = keyringmgr.get_keyring()
    local new_keys = get_keys(keyring, address, port);

    -- Check for existing entires for playername
    for _, login in ipairs(new_keys.logins) do
        if login.playername and login.playername == playername then
            return login
        end
    end
    error("No login found on " .. address .. ":" .. port .. " for player " .. playername)
end

function keyringmgr.remove_login(address, port, playername)
    assert(type(port) == "number")

    local keyring = keyringmgr.get_keyring()
    local new_keys = get_keys(keyring, address, port);
    for i = 1, #new_keys.logins do
        local login = new_keys.logins[i]

        if (login.playername == playername) then
            table.remove(new_keys.logins, i)
            break
        end
    end

    rewrite_keys(keyring, address, port, new_keys)
end

function keyringmgr.delete_keys(address, port)
    local keyring = keyringmgr.get_keyring()
    delete_keys(keyring, address, port)
    save_keyring(keyring)
end

function keyringmgr.get_last_login(address, port)
    local playername = get_keys(keyringmgr.get_keyring(), address, port).last_login
    if playername then
        return keyringmgr.get_login(address, port, playername)
    end
    return false
end