gm_webapi_http.lua

--Localizations
local isstring		= isstring
local isnumber		= isnumber
local istable		= istable
local isfunction	= isfunction
local ErrorNoHalt	= ErrorNoHalt
local CurTime		= CurTime
local httpPost 		= http.Post
local utilJSONToTable	= util.JSONToTable

local apiUrl = ""
local apiHeaders = {}

local methods = {}


--[[
  Doccumentation: https://github.com/The-Lord-of-Owls/gm_webapi/tree/main#apiadd-id-route-cback-onerror-cachettl-customheaders-
]]
local function Add( id, route, cback, onError, cacheTTL, customHeaders )
	--Check if an id was provided
	if not id or not isstring( id ) then
		return ErrorNoHalt( "API ERROR: You must provide an id when setting up a new API method!\n" )
	end

	--Check if a route was provided
	if not route or not isstring( route ) then
		return ErrorNoHalt( "API ERROR: You must specify a route when setting up a new API method!\n" )
	end

	--Check if a callback function was provided
	if not cback or not isfunction( cback ) then
		return ErrorNoHalt( "API ERROR: You must provide a callback function when setting up a new API method!\n" )
	end


	--Setup method object
	local method = {
		route = route,
		cback = cback
	}

	--Specify optional custom headers for method
	if customHeaders and istable( customHeaders ) then
		method.headers = customHeaders
	elseif customHeaders then
		ErrorNoHalt( "API WARNING: Custom route headers must be in a keyvalue table format. The API method has been created but custom headers have not been set for it!\n" )
	end

	--Optional error response
	if onError and isfunction( onError ) then
		method.onError = onError
	elseif onError then
		ErrorNoHalt( "API WARNING: Custom onError must be a function, the API method has been created without custom error handling!\n" )
	end

	--Handle if we will cache the value
	if cacheTTL and isnumber( cacheTTL ) then
		method.cacheTTL = cacheTTL
		method.nextCache = 0
		method.waitReq = false
	elseif cacheTTL then
		ErrorNoHalt( "API WARNING: cacheTTL for API methods must be a number value, the API method has been created with caching disabled!\n" )
	end

	--Make the method object accessible
	methods[ id ] = method
end

--[[
	Doccumentation: https://github.com/The-Lord-of-Owls/gm_webapi/tree/main#apiremove-id-
]]
local function Remove( id )
	if not id or not isstring( id ) then
		return ErrorNoHalt( "API WARNING: Please provide a id string for the method you want to remove!\n" )
	end

	methods[ id ] = nil
end

--[[
	Doccumentation: https://github.com/The-Lord-of-Owls/gm_webapi/tree/main#apicall-id-params-
]]
local function Call( id, params )
	--Check if the API url has been set
	if apiUrl == "" then
		return ErrorNoHalt( "API ERROR: API URL has not been set, aborting API call! Please make sure to run api.SetURL before calling any methods!\n" )
	end

	--Check if the API method exists
	if not methods[ id ] then
		return ErrorNoHalt( "API ERROR: The API method '" .. id .. "' does not exist!\n" )
	end

	--The API method
	local apiMethod = methods[ id ]

	--Check if the API has a proper callback function
	if not apiMethod.cback then
		return ErrorNoHalt( "API ERROR: The API method '" .. id .. "' does not have a callback function!\n" )
	end

	local curTime = CurTime()

	--Check if should return cached value
	if apiMethod.waitReq or ( apiMethod.nextCache and apiMethod.nextCache >= curTime and apiMethod.cacheRes ~= "" ) then
		apiMethod.cback( apiMethod.cacheRes )

		return
	end

	apiMethod.waitReq = true
	httpPost( apiUrl .. apiMethod.route, params or {}, function( res, size, headers, code )
		local parsed = utilJSONToTable( res )

		--Update the cache
		if apiMethod.cacheTTL and curTime > apiMethod.nextCache then
			apiMethod.nextCache = curTime + apiMethod.cacheTTL
			apiMethod.cacheRes = parsed.resData
			apiMethod.waitReq = false
		end

		apiMethod.cback( parsed.resData )
	end, apiMethod.onError or ErrorNoHalt, apiMethod.headers or apiHeaders )
end

--[[
  Doccumentation: https://github.com/The-Lord-of-Owls/gm_webapi/tree/main#apigettable
]]
local function GetTable()
	return methods or {}
end


--[[
	Doccumentation: https://github.com/The-Lord-of-Owls/gm_webapi/tree/main#apiseturl-url-
]]
local function SetUrl( url )
	if not url and isstring( url ) then
		return ErrorNoHalt( "API ERROR: Please provide a valid url string for the API!\n" )
	end

	apiUrl = url
end


--[[
	Doccumentation: https://github.com/The-Lord-of-Owls/gm_webapi/tree/main#apiaddheader-header-value-
]]
local function AddHeader( header, value )
	if not header or not isstring( header ) then
		return ErrorNoHalt( "API ERROR: Please provide a proper header string!\n" )
	end

	if not value or not isstring( value ) then
		return ErrorNoHalt( "API ERROR: Please provide a proper header string value!\n" )
	end

	apiHeaders[ header ] = value
end

--[[
	Doccumentation: https://github.com/The-Lord-of-Owls/gm_webapi/tree/main#apisetheader-header-value-
]]
local function SetHeader( header, value )
	if not header or not isstring( header ) then
		return ErrorNoHalt( "API ERROR: Please provide a proper header string!\n" )
	end

	if not value or not isstring( value ) then
		return ErrorNoHalt( "API ERROR: Please provide a proper header string value!\n" )
	end

	apiHeaders[ header ] = value
end

--[[
  Doccumentation: https://github.com/The-Lord-of-Owls/gm_webapi/tree/main#apiremoveheader-header-
]]
local function RemoveHeader( header )
	if not header or not isstring( header ) then
		return ErrorNoHalt( "API ERROR: Please provide a proper header string!\n" )
	end

	apiHeaders[ header ] = nil
end


--[[
	Setting up our API library table
	Doccumentation: https://github.com/The-Lord-of-Owls/gm_webapi/blob/main/README.md#apicall-id-params-
]]
api = setmetatable( {
	Add = Add,
	Remove = Remove,
	Call = Call,
	GetTable = GetTable,
	SetUrl = SetUrl,
	AddHeader = AddHeader,
	SetHeader = SetHeader,
	RemoveHeader = RemoveHeader
}, {
	__metatable = "WebAPI Handler",
	__call = function( self, ... )
		Call( ... )
	end
} )

--[[Was used during testing]]
SetUrl( "http://localhost:5000/api" )
Add( "test", "/test", function( res )
	PrintTable(res)
end, nil, 10 )

timer.Create( "testing-api", 1, 0, function()
	Call( "test", { steamId = "00000000000000001" } )
end )