---@class DBMCoreNamespace
local private = select(2, ...)

---@class DBM
local DBM = private:GetPrototype("DBM")
local CL = DBM_COMMON_L

---@class DBMTest
local test = private:GetPrototype("DBMTest")
DBM.Test = test

-- Indicates whether a test is currently running.
test.testRunning = false

-- Overriden by DBM-Test once loaded.
-- This field is intentionally set in an odd way to prevent LuaLS from suggesting this function.
local traceField = "Trace"
test[traceField] = function() end

local LoadAddOn = _G.C_AddOns.LoadAddOn or LoadAddOn ---@diagnostic disable-line:deprecated

function test:Load()
	local loaded, err = LoadAddOn("DBM-Test")
	if not loaded then
		DBM:AddMsg("Failed to load DBM-Test: " .. (_G["ADDON_" .. err] or CL.UNKNOWN))
		return loaded, err
	end
	return true
end

function test:LoadAllTests()
	local numTestAddOnsFound = 0
	if not self:Load() then
		return nil
	end
	for i = 1, C_AddOns.GetNumAddOns() do
		if C_AddOns.GetAddOnMetadata(i, "X-DBM-Test") then
			numTestAddOnsFound = numTestAddOnsFound + 1
			C_AddOns.LoadAddOn(i)
		end
	end
	return numTestAddOnsFound
end

function test:TestsLoaded()
	return self.Registry ~= nil and #self.Registry.sortedTests > 0
end

function test:HandleCommand(testName, timeWarp)
	timeWarp = timeWarp and tonumber(timeWarp:match("(%d+)"))
	local numTestAddOnsFound = self:LoadAllTests()
	if not numTestAddOnsFound then return end
	if numTestAddOnsFound == 0 then
		DBM:AddMsg("No test AddOns installed, install an alpha or dev version of DBM to get DBM-Test-* mods.")
	end
	if testName:lower() == "list" or testName:lower() == "help" then
		DBM:AddMsg("Available tests:")
		for _, v in ipairs(self.Registry.sortedTests) do
			DBM:AddMsg("  " .. v)
		end
		if #self.Registry.sortedTests == 0 then
			DBM:AddMsg("  (none)")
		end
		DBM:AddMsg("/dbm test <name> <time warp factor> -- execute a test")
		DBM:AddMsg("/dbm test * <time warp factor> -- run all tests")
		DBM:AddMsg("<name> can be a prefix, e.g., /dbm test Dragonflight runs all tests for Dragonflight.")
		DBM:AddMsg("/dbm test clear -- clear exported test data")
	elseif testName:lower() == "stop" then
		test:StopTests()
		DBM:AddMsg("Stopping running tests.")
	elseif testName:lower() == "clear" then
		DBM_TestResults_Export = {}
		DBM:AddMsg("Cleared exported test results.")
	else
		local tests = {}
		if testName == "*" then
			testName = ""
		end
		for _, v in ipairs(self.Registry.sortedTests) do
			if v:sub(1, #testName) == testName then
				tests[#tests + 1] = v
			end
		end
		if #tests == 0 then
			DBM:AddMsg("No tests matching prefix " .. testName .. " found, run /dbm test list to see available tests.")
			return
		end
		local successes = 0
		self:RunTests(tests, timeWarp, nil, function(event, test, testOptions, report, count, totalTests)
			if event ~= "TestFinish" then return end
			DBM:AddMsg("Test " .. test.name .. " finished, result: " .. report:GetResult())
			if report:GetResult() == "Success" then
				successes = successes + 1
			end
			if report:HasDiff() then
				report:ReportDiff()
			end
			if report:HasErrors() then
				report:ReportErrors()
			end
			if count == totalTests and totalTests > 1 then
				DBM:AddMsg(("%d/%d tests succeeded!"):format(successes, totalTests))
			end
		end)
	end
end

---@type table<Frame>
test.framesForTimeWarp = {}

function test:RegisterTimeWarpFrame(frame)
	-- Frames are registered on DBM load -- which is before the full testing module containing the time warper loads
	if test.TimeWarper then
		test.TimeWarper:RegisterFrame(frame)
	else
		test.framesForTimeWarp[frame] = true
	end
end

-- Expose DBM private's namespace for tests.
-- These functions are intentionally disabled in release builds to prevent people from using these to tamper with DBM's private namespace in release builds.

local function checkDevBuild()
--@non-alpha@
	error("this function is only available in dev and alpha builds of DBM", 3)
	do return false end -- Safety to prevent people from just overriding error() to circumvent the alpha check.
--@end-non-alpha@
	return true
end

local localHooks = {}
local restoreLocalHooks = {}
local restorePrivates = {}

-- Temporarily change the value of a field in DBM's private namespace or update a local variable in a file.
-- Updating locals works by files registering a callback via RegisterLocalHook below.
function test:HookPrivate(key, value)
	if not checkDevBuild() then return end
	if localHooks[key] then
		restoreLocalHooks[key] = restoreLocalHooks[key] or {}
		for _, v in ipairs(localHooks[key]) do
			local old = v(value)
			if restoreLocalHooks[key][v] == nil then -- handle nested hooking calls
				restoreLocalHooks[key][v] = old
			end
		end
	end
	if private[key] ~= nil then -- FIXME: support privates that are currently nil
		if restorePrivates[key] == nil then
			restorePrivates[key] = private[key]
		end
		private[key] = value
	end
end

-- Register a function to change a file-local variable temporarily via HookPrivate
function test:RegisterLocalHook(id, hookingFunc)
	local entries = localHooks[id] or {}
	localHooks[id] = entries
	entries[#entries + 1] = hookingFunc
end

function test:UnhookPrivates()
	if not checkDevBuild() then return end
	for k, v in pairs(restorePrivates) do
		private[k] = v
	end
	table.wipe(restorePrivates)
	for _, v in pairs(restoreLocalHooks) do
		for func, val in pairs(v) do
			func(val)
		end
	end
	table.wipe(restoreLocalHooks)
end

function test:GetPrivate()
	if not checkDevBuild() then error() end
	return private
end