// Copyright 2025 Alibaba Group Holding Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"strings"
	"time"

	"k8s.io/apimachinery/pkg/runtime"
	"knative.dev/pkg/injection"
	"knative.dev/pkg/signals"

	"github.com/alibaba/opensandbox/ingress/pkg/flag"
	"github.com/alibaba/opensandbox/ingress/pkg/proxy"
	"github.com/alibaba/opensandbox/ingress/pkg/renewintent"
	"github.com/alibaba/opensandbox/ingress/pkg/sandbox"
	"github.com/alibaba/opensandbox/ingress/pkg/signature"
	"github.com/alibaba/opensandbox/ingress/pkg/telemetry"
	slogger "github.com/alibaba/opensandbox/internal/logger"
	"github.com/alibaba/opensandbox/internal/version"
)

func main() {
	version.EchoVersion("OpenSandbox Ingress")

	flag.InitFlags()

	cfg := injection.ParseAndGetRESTConfigOrDie()
	cfg.ContentType = runtime.ContentTypeProtobuf
	cfg.UserAgent = "opensandbox-ingress/" + version.GitCommit

	ctx := signals.NewContext()
	ctx = withLogger(ctx, flag.LogLevel)

	otelShutdown, err := telemetry.Init(ctx)
	if err != nil {
		log.Printf("OpenTelemetry metrics disabled (continuing without OTLP): %v", err)
		otelShutdown = nil
	}
	if otelShutdown != nil {
		defer func() {
			shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 5*time.Second)
			defer shutdownCancel()
			_ = otelShutdown(shutdownCtx)
		}()
	}

	// Create sandbox provider factory
	providerFactory := sandbox.NewProviderFactory(
		cfg,
		time.Second*30, // resync period
	)

	// Create sandbox provider based on provider type
	sandboxProvider, err := providerFactory.CreateProvider(sandbox.ProviderType(flag.ProviderType))
	if err != nil {
		log.Panicf("Failed to create sandbox provider: %v", err)
	}

	// Start provider (includes cache sync)
	if err := sandboxProvider.Start(ctx); err != nil {
		log.Panicf("Failed to start sandbox provider: %v", err)
	}

	var renewPublisher renewintent.Publisher
	if flag.RenewIntentEnabled {
		redisClient, err := renewintent.RedisClientFromDSN(flag.RenewIntentRedisDSN)
		if err != nil {
			log.Panicf("Failed to create Redis client for renew-intent: %v", err)
		}
		renewPublisher = renewintent.NewRedisPublisher(ctx, redisClient, renewintent.RedisPublisherConfig{
			QueueKey:    flag.RenewIntentQueueKey,
			QueueMaxLen: flag.RenewIntentQueueMaxLen,
			MinInterval: time.Duration(flag.RenewIntentMinIntervalSec) * time.Second,
			Logger:      proxy.Logger,
		})
	}

	var secure *signature.Verifier
	if keyStr := strings.TrimSpace(flag.SecureAccessKeys); keyStr != "" {
		keys, err := signature.ParseKeys(flag.SecureAccessKeys)
		if err != nil {
			log.Panicf("parse secure-access-keys: %v", err)
		}
		secure = &signature.Verifier{Keys: keys}
	}

	// Create reverse proxy with sandbox provider
	reverseProxy := proxy.NewProxy(ctx, sandboxProvider, proxy.Mode(flag.Mode), renewPublisher, secure)
	mux := http.NewServeMux()
	mux.Handle("/", reverseProxy)
	mux.HandleFunc("/status.ok", proxy.Healthz)

	if err := http.ListenAndServe(fmt.Sprintf(":%v", flag.Port), mux); err != nil {
		log.Panicf("Error starting http server: %v", err)
	}

	panic("unreachable")
}

func withLogger(ctx context.Context, logLevel string) context.Context {
	logger := slogger.MustNew(slogger.Config{Level: logLevel}).Named("opensandbox.ingress")
	return proxy.WithLogger(ctx, logger)
}