package profile

import (
	"context"
	"fmt"
	"sync"
	"time"

	"github.com/safing/portbase/config"
	"github.com/safing/portbase/modules"
	"github.com/safing/portmaster/intel/filterlists"
	"github.com/safing/portmaster/profile/endpoints"
)

var (
	cfgLock sync.RWMutex

	cfgDefaultAction    uint8
	cfgEndpoints        endpoints.Endpoints
	cfgServiceEndpoints endpoints.Endpoints
	cfgFilterLists      []string
)

func registerConfigUpdater() error {
	return module.RegisterEventHook(
		"config",
		"config change",
		"update global config profile",
		func(ctx context.Context, _ interface{}) error {
			return updateGlobalConfigProfile(ctx, nil)
		},
	)
}

const globalConfigProfileErrorID = "profile:global-profile-error"

func updateGlobalConfigProfile(ctx context.Context, task *modules.Task) error {
	cfgLock.Lock()
	defer cfgLock.Unlock()

	var err error
	var lastErr error

	action := cfgOptionDefaultAction()
	switch action {
	case "permit":
		cfgDefaultAction = DefaultActionPermit
	case "ask":
		cfgDefaultAction = DefaultActionAsk
	case "block":
		cfgDefaultAction = DefaultActionBlock
	default:
		// TODO: module error?
		lastErr = fmt.Errorf(`default action "%s" invalid`, action)
		cfgDefaultAction = DefaultActionBlock // default to block in worst case
	}

	list := cfgOptionEndpoints()
	cfgEndpoints, err = endpoints.ParseEndpoints(list)
	if err != nil {
		// TODO: module error?
		lastErr = err
	}

	list = cfgOptionServiceEndpoints()
	cfgServiceEndpoints, err = endpoints.ParseEndpoints(list)
	if err != nil {
		// TODO: module error?
		lastErr = err
	}

	list = cfgOptionFilterLists()
	cfgFilterLists, err = filterlists.ResolveListIDs(list)
	if err != nil {
		lastErr = err
	}

	// build global profile for reference
	profile := New(SourceSpecial, "global-config", "", nil)
	profile.Name = "Global Configuration"
	profile.Internal = true

	newConfig := make(map[string]interface{})
	// fill profile config options
	for key, value := range cfgStringOptions {
		newConfig[key] = value()
	}
	for key, value := range cfgStringArrayOptions {
		newConfig[key] = value()
	}
	for key, value := range cfgIntOptions {
		newConfig[key] = value()
	}
	for key, value := range cfgBoolOptions {
		newConfig[key] = value()
	}

	// expand and assign
	profile.Config = config.Expand(newConfig)

	// save profile
	err = profile.Save()
	if err != nil && lastErr == nil {
		// other errors are more important
		lastErr = err
	}

	// If there was any error, try again later until it succeeds.
	if lastErr == nil {
		module.Resolve(globalConfigProfileErrorID)
	} else {
		// Create task after first failure.
		if task == nil {
			task = module.NewTask(
				"retry updating global config profile",
				updateGlobalConfigProfile,
			)
		}

		// Schedule task.
		task.Schedule(time.Now().Add(15 * time.Second))

		// Add module warning to inform user.
		module.Warning(
			globalConfigProfileErrorID,
			"Internal Settings Failure",
			fmt.Sprintf("The app settings layering system failed to process the global settings. This means that some global settings might not be applied correctly. You can try restarting the Portmaster to resolve this problem. Refer to the error for more details: %s", err),
		)
	}

	return lastErr
}