local nk = require("nakama")

local utils = {}

utils.ADMIN_ROLES = { ["admin"] = true, ["moderator"] = true, ["owner"] = true }
utils.SYSTEM_USER_ID = "00000000-0000-0000-0000-000000000000"

function utils.is_admin(context)
    if not context.user_id then return false end
    
    local status, account = pcall(nk.account_get_id, context.user_id)
    if not status or not account then return false end
    
    local metadata = {}
    if type(account.user.metadata) == "string" then
        status, metadata = pcall(nk.json_decode, account.user.metadata)
        if not status then metadata = {} end
    else
        metadata = account.user.metadata or {}
    end
    
    local role = metadata.role or ""
    return utils.ADMIN_ROLES[role] == true
end

function utils.is_match_host(context, match_id)
    if not context.user_id or not match_id then return false end
    local status, match = pcall(nk.match_get, match_id)
    if not status or not match then return false end

    -- Needs to decode match.state if you're using authoritative matches
    -- Simplified for lua translation:
    local state = {}
    if match.state then
        status, state = pcall(nk.json_decode, match.state)
        if not status then state = {} end
    end
    return state.hostUserId == context.user_id
end

function utils.require_admin(context)
    if not utils.is_admin(context) then
        error("Admin privileges required")
    end
end

function utils.require_admin_or_host(context, match_id)
    if not utils.is_admin(context) and not utils.is_match_host(context, match_id) then
        error("Admin or host privileges required")
    end
end

-- Channel type constants for nk.channel_id_build (Nakama Lua runtime).
-- NOTE: these differ from the Godot client's NakamaSocket.ChannelType enum.
utils.CHANNEL_TYPE_ROOM = 1
utils.CHANNEL_TYPE_DIRECT = 2
utils.CHANNEL_TYPE_GROUP = 3

-- Resolve a chat channel identifier for admin chat RPCs.
--
-- The client may send either an already-hashed Nakama channel ID, or a friendly
-- room name (e.g. "social_global"). A raw room name is NOT a valid channel ID for
-- nk.channel_messages_list, so we build the canonical hashed ID via the
-- authoritative nk.channel_id_build API (system user as sender → global room).
-- Returns the resolved channel ID, or the original value if it already looks
-- hashed / can't be built.
function utils.resolve_channel_id(channel_id)
    if not channel_id or channel_id == "" then
        return ""
    end
    -- A hashed Nakama channel ID contains a '.' separator; a plain room name does
    -- not. Only treat dot-free values as room names needing resolution.
    if string.find(channel_id, "%.") then
        return channel_id
    end
    local status, built = pcall(nk.channel_id_build, "", channel_id, utils.CHANNEL_TYPE_ROOM)
    if status and built and built ~= "" then
        return built
    end
    return channel_id
end

return utils