package main

import (
	"context"
	"crypto/ed25519"
	"crypto/rand"
	"encoding/base64"
	"errors"
	"fmt"
	"log/slog"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/iliaivanov/spec-kit-remote/cmd/dev-pod-api/internal/api"
	"github.com/iliaivanov/spec-kit-remote/cmd/dev-pod-api/internal/forgejo"
	"github.com/iliaivanov/spec-kit-remote/cmd/dev-pod-api/internal/k8s"
	"github.com/iliaivanov/spec-kit-remote/cmd/dev-pod-api/internal/model"
	"github.com/iliaivanov/spec-kit-remote/cmd/dev-pod-api/internal/store"
)

func main() {
	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))
	slog.SetDefault(logger)

	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
	defer stop()

	// Database
	dbURL := os.Getenv("DATABASE_URL")
	if dbURL == "" {
		slog.Error("DATABASE_URL is required")
		os.Exit(1)
	}

	pool, err := store.NewPool(ctx, dbURL)
	if err != nil {
		slog.Error("failed to connect to database", "error", err)
		os.Exit(1)
	}
	defer pool.Close()

	st := store.New(pool)
	if err := st.Migrate(ctx); err != nil {
		slog.Error("failed to run migrations", "error", err)
		os.Exit(1)
	}
	slog.Info("database migrations complete")

	// Bootstrap admin user if ADMIN_BOOTSTRAP_KEY is set and admin doesn't exist
	bootstrapAdmin(ctx, st, logger)

	// Kubernetes client
	k8sCfg := k8s.ConfigFromEnv()
	k8sClient, err := k8s.NewClient(k8sCfg)
	if err != nil {
		slog.Error("failed to create k8s client", "error", err)
		os.Exit(1)
	}

	// Resource sampler (background goroutine)
	sampler := k8s.NewResourceSampler(k8sClient, st, logger)
	go sampler.Start(ctx)

	// Forgejo integration (optional)
	var forgejoManager api.ForgejoManager
	forgejoAdminUser := os.Getenv("FORGEJO_ADMIN_USER")
	forgejoAdminPassword := os.Getenv("FORGEJO_ADMIN_PASSWORD")
	if forgejoAdminUser != "" && forgejoAdminPassword != "" {
		forgejoManager = forgejo.NewClient(k8sCfg.ForgejoURL, forgejoAdminUser, forgejoAdminPassword)
		slog.Info("forgejo integration enabled", "url", k8sCfg.ForgejoURL)
	} else {
		slog.Info("forgejo integration disabled (FORGEJO_ADMIN_USER/FORGEJO_ADMIN_PASSWORD not set)")
	}

	// web-tui: JWT signer (optional — only activates /api/v1/auth/exchange
	// and /.well-known/jwks.json when WEBTUI_JWT_SEED is set).
	jwtSigner := loadJWTSigner(logger)

	// web-tui: session-host manager (optional — activates
	// /api/v1/pods/session-host endpoints when WEBTUI_ENABLED=1).
	var sessionHost api.SessionHostManager
	if os.Getenv("WEBTUI_ENABLED") == "1" {
		spec := k8s.SessionHostSpec{
			Image:                   envOr("WEBTUI_GOLDEN_IMAGE", "10.22.0.56:30500/dev-golden:v2"),
			PortWatchImage:          envOr("WEBTUI_PORTWATCH_IMAGE", "10.22.0.56:30500/web-tui-port-watch:dev"),
			ApexDomain:              envOr("WEBTUI_APEX_DOMAIN", "spinoff.dev"),
			ClusterIssuer:           envOr("WEBTUI_CLUSTER_ISSUER", "letsencrypt-cloudflare-dns01"),
			GatewayService:          envOr("WEBTUI_GATEWAY_SERVICE", "web-tui-gateway"),
			GatewayServiceNamespace: envOr("WEBTUI_GATEWAY_NAMESPACE", "web-tui"),
		}
		sessionHost = &sessionHostAdapter{client: k8sClient, spec: spec}
		logger.Info("web-tui session-host manager enabled", "apex", spec.ApexDomain)
	}

	// Runner cleanup goroutine
	runnerCleaner := k8s.NewRunnerCleaner(k8sClient, st, logger)
	go runnerCleaner.Start(ctx)

	// HTTP server
	srv := &api.Server{
		Store:         st,
		K8s:           k8sClient,
		Cluster:       k8sClient,
		Users:         st,
		Usage:         st,
		Forgejo:       forgejoManager,
		Runners:       st,
		RunnerPods:    k8sClient,
		Logger:        logger,
		GenerateKey:   store.GenerateAPIKey,
		JWTSigner:     jwtSigner,
		SessionHost:   sessionHost,
		WebhookSecret:      os.Getenv("FORGEJO_WEBHOOK_SECRET"),
		ForgejoRunnerToken: os.Getenv("FORGEJO_RUNNER_TOKEN"),
	}

	router := api.NewRouter(srv)

	port := os.Getenv("PORT")
	if port == "" {
		port = "8080"
	}

	httpSrv := &http.Server{
		Addr:              ":" + port,
		Handler:           router,
		ReadHeaderTimeout: 10 * time.Second,
		ReadTimeout:       30 * time.Second,
		WriteTimeout:      60 * time.Second,
	}

	go func() {
		<-ctx.Done()
		slog.Info("shutting down server")
		shutdownCtx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
		defer cancel()
		if err := httpSrv.Shutdown(shutdownCtx); err != nil {
			slog.Error("server shutdown error", "error", err)
		}
	}()

	slog.Info("starting dev-pod-api", "port", port)
	if err := httpSrv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
		slog.Error("server failed", "error", err)
		os.Exit(1)
	}
	slog.Info("server stopped")
}

// envOr returns the named env var if set, otherwise fallback.
func envOr(key, fallback string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return fallback
}

// loadJWTSigner returns a signer backed by the base64-encoded seed in
// WEBTUI_JWT_SEED (32-byte Ed25519 seed). Missing env → nil signer →
// /api/v1/auth/exchange returns 503, which is fine when web-tui isn't
// in use.
func loadJWTSigner(logger *slog.Logger) api.JWTSigner {
	raw := os.Getenv("WEBTUI_JWT_SEED")
	var seed []byte
	if raw == "" {
		// Dev convenience: synthesise a fresh seed at startup. All JWTs
		// issued with this key become invalid on restart. For prod set
		// WEBTUI_JWT_SEED from a Secret.
		seed = make([]byte, ed25519.SeedSize)
		if _, err := rand.Read(seed); err != nil {
			logger.Error("failed to generate JWT seed", "error", err)
			return nil
		}
		logger.Warn("WEBTUI_JWT_SEED unset — generated an ephemeral key; tokens will be invalidated on restart")
	} else {
		var err error
		seed, err = base64.StdEncoding.DecodeString(raw)
		if err != nil {
			logger.Error("WEBTUI_JWT_SEED is not valid base64", "error", err)
			return nil
		}
	}
	signer, err := api.NewEd25519SignerFromSeed(envOr("WEBTUI_JWT_KID", "webtui-1"), seed)
	if err != nil {
		logger.Error("failed to construct JWT signer", "error", err)
		return nil
	}
	return signer
}

// sessionHostAdapter bridges k8s.Client into the api.SessionHostManager
// interface, translating k8s.SessionHostStatus → api.SessionHostStatus.
type sessionHostAdapter struct {
	client *k8s.Client
	spec   k8s.SessionHostSpec
}

func (a *sessionHostAdapter) EnsureForUser(ctx context.Context, user string) (api.SessionHostStatus, error) {
	s, err := a.client.EnsureSessionHost(ctx, user, a.spec)
	return toAPIStatus(s), err
}

func (a *sessionHostAdapter) StatusForUser(ctx context.Context, user string) (api.SessionHostStatus, error) {
	s, err := a.client.SessionHostStatusForUser(ctx, user)
	return toAPIStatus(s), err
}

func toAPIStatus(s k8s.SessionHostStatus) api.SessionHostStatus {
	return api.SessionHostStatus{
		Ready:             s.Ready,
		PodName:           s.PodName,
		Namespace:         s.Namespace,
		CertReady:         s.CertReady,
		CertPendingReason: s.CertPendingReason,
		AtchSessionCount:  s.AtchSessionCount,
		CreatedAt:         s.CreatedAt,
	}
}

// bootstrapAdmin creates an admin user with an API key on first run.
// Set ADMIN_BOOTSTRAP_KEY to a pre-chosen key, or leave empty to auto-generate one.
func bootstrapAdmin(ctx context.Context, st *store.Store, logger *slog.Logger) {
	// Check if admin user already exists
	_, err := st.GetUser(ctx, "admin")
	if err == nil {
		logger.Info("admin user already exists, skipping bootstrap")
		return
	}
	if !errors.Is(err, store.ErrNotFound) {
		logger.Error("failed to check for admin user", "error", err)
		return
	}

	// Create admin user with elevated quotas
	adminQuota := model.Quota{
		MaxConcurrentPods: 10,
		MaxCPUPerPod:      16,
		MaxRAMGBPerPod:    32,
		MonthlyPodHours:   10000,
		MonthlyAIRequests: 100000,
	}
	if _, err := st.CreateUser(ctx, "admin", adminQuota); err != nil {
		logger.Error("failed to create admin user", "error", err)
		return
	}

	// Use pre-set key or generate one
	bootstrapKey := os.Getenv("ADMIN_BOOTSTRAP_KEY")
	var plainKey, keyHash string
	if bootstrapKey != "" {
		plainKey = bootstrapKey
		keyHash = store.HashKey(plainKey)
	} else {
		var genErr error
		plainKey, keyHash, genErr = store.GenerateAPIKey()
		if genErr != nil {
			logger.Error("failed to generate admin API key", "error", genErr)
			if delErr := st.DeleteUser(ctx, "admin"); delErr != nil {
				logger.Error("rollback: failed to delete orphaned admin user", "error", delErr)
			}
			return
		}
	}

	if err := st.CreateAPIKey(ctx, "admin", model.RoleAdmin, keyHash); err != nil {
		logger.Error("failed to create admin API key", "error", err)
		if delErr := st.DeleteUser(ctx, "admin"); delErr != nil {
			logger.Error("rollback: failed to delete orphaned admin user", "error", delErr)
		}
		return
	}

	logger.Info("admin user bootstrapped successfully")
	// Print the key to stdout so it can be captured from logs
	fmt.Fprintf(os.Stderr, "\n=== ADMIN API KEY (save this, it won't be shown again) ===\n%s\n===\n\n", plainKey)
}