// Copyright 2026 Beacon Contributors
// SPDX-License-Identifier: AGPL-3.0-or-later

// Package router wires all HTTP routes onto the Chi router and injects
// dependencies (hub, reader, ingest workers) into the handler closures.
// REST routes are mounted under /api/v1; its admin subtree requires a bearer key.
package router

import (
	"net/http"

	"github.com/go-chi/chi/v5"
	"github.com/go-chi/chi/v5/middleware"

	"github.com/MeshCore-Beacon/beacon-server/internal/api"
	"github.com/MeshCore-Beacon/beacon-server/internal/api/handlers"
	mw "github.com/MeshCore-Beacon/beacon-server/internal/api/middleware"
	"github.com/MeshCore-Beacon/beacon-server/internal/hub"
	"github.com/MeshCore-Beacon/beacon-server/internal/ingest"
	"github.com/MeshCore-Beacon/beacon-server/internal/ws"
	httpSwagger "github.com/swaggo/http-swagger"
)

// New builds and returns the top-level Chi router.
//
// Route shape:
//
//	/ws                → WebSocket (public in v1)
//	/api/v1/           → public group
//	  /info            → server info and minimum client versions
//	  /packets         → packets subrouter
//	  /nodes           → nodes subrouter
//	  /brokers         → brokers subrouter
//	  /observers       → observers subrouter
//	  /channels        → channels subrouter
//	  /iatas           → iatas subrouter
//	  /regions         → regions subrouter
//	  /stats           → stats subrouter
//
// Admin endpoints require a configured bearer key.
func New(h *hub.Hub, reader api.Reader, workers []*ingest.Worker, opts Options) http.Handler {
	r := chi.NewRouter()

	// ── CORS ─────────────────────────────────────────────────────────────────
	allowedOrigins := opts.CORS.AllowedOrigins
	if len(allowedOrigins) == 0 {
		allowedOrigins = []string{"*"}
	}
	allowedMethods := opts.CORS.AllowedMethods
	if len(allowedMethods) == 0 {
		allowedMethods = []string{"GET", "HEAD", "OPTIONS"}
	}
	allowedHeaders := opts.CORS.AllowedHeaders
	if len(allowedHeaders) == 0 {
		allowedHeaders = []string{"Accept", "Authorization", "Content-Type"}
	}
	maxAge := opts.CORS.MaxAge
	if maxAge == 0 {
		maxAge = 300
	}
	// Capture only values used by this router. Do not retain Config, credentials
	// or caller-owned slices in the admin response.
	adminConfig := api.AdminConfig{
		Auth: api.AdminAuthConfig{Configured: opts.Auth.APIKey != ""},
		CORS: api.AdminCORSConfig{
			AllowedOrigins:   append([]string{}, allowedOrigins...),
			AllowedMethods:   append([]string{}, allowedMethods...),
			AllowedHeaders:   append([]string{}, allowedHeaders...),
			AllowCredentials: opts.CORS.AllowCredentials,
			MaxAge:           maxAge,
		},
		Ingest: api.AdminIngestConfig{BrokerCount: len(workers)},
		Mobile: api.AdminMobileConfig{MinAppVersion: opts.MinAppVersion},
		Web:    api.AdminWebConfig{MinWebVersion: opts.MinWebVersion},
	}
	info := api.Info{ServerVersion: opts.ServerVersion}
	if opts.MinAppVersion != "" {
		info.MinAppVersion = &opts.MinAppVersion
	}
	if opts.MinWebVersion != "" {
		info.MinWebVersion = &opts.MinWebVersion
	}
	runtimeConfig := mw.NewRuntimeConfig(adminConfig, []string{"Retry-After"})
	r.Use(runtimeConfig.CORS)

	// ── Global middleware ────────────────────────────────────────────────────
	r.Use(middleware.RequestID)
	r.Use(mw.TrustedProxyIP(opts.Server.TrustedProxies))
	r.Use(mw.RequestLogger)
	r.Use(middleware.Recoverer)
	r.Use(middleware.CleanPath)
	r.Use(middleware.StripSlashes)

	// ── Swagger UI ──────────────────────────────────────────────────────────
	r.Get("/swagger", func(w http.ResponseWriter, r *http.Request) {
		http.Redirect(w, r, "/swagger/index.html", http.StatusMovedPermanently)
	})

	r.Get("/swagger/*", httpSwagger.Handler(
		httpSwagger.URL("/swagger/doc.json"),
	))

	// ── WebSocket ────────────────────────────────────────────────────────────
	r.Get("/ws", ws.Handler(h, reader, opts.MaxConnsPerIP, opts.MaxConnectsPerMinute, opts.WSAllowedOrigins))

	// ── Public REST API (v1) ─────────────────────────────────────────────────
	r.Route("/api/v1", func(r chi.Router) {
		r.Use(mw.RateLimit(opts.RateLimit))
		// Public group — no authentication required.
		r.Group(func(r chi.Router) {
			r.Mount("/packets", handlers.PacketsRouter(reader))
			r.Mount("/nodes", handlers.NodesRouter(reader))
			r.Mount("/brokers", handlers.BrokersRouter(workers))
			r.Mount("/observers", handlers.ObserversRouter(reader))
			r.Mount("/channels", handlers.ChannelsRouter(reader))
			r.Mount("/messages", handlers.MessagesRouter(reader))
			r.Mount("/iatas", handlers.IATAsRouter(reader))
			r.Mount("/regions", handlers.RegionsRouter(reader))
			r.Mount("/routes", handlers.RoutesRouter(reader))
			r.Mount("/scopes", handlers.ScopesRouter(reader, opts.Scopes))
			r.Mount("/stats", handlers.StatsRouter(reader, handlers.StatsOptions{Scopes: opts.Scopes, SeriesWindow: opts.RollupRetention}))
			r.Mount("/traces", handlers.TracesRouter(reader))
			r.Mount("/info", handlers.InfoRouter(info))
		})

		// Protect the entire subtree, including its root and unknown paths.
		r.Mount("/admin", mw.BearerAuth(opts.Auth.APIKey, handlers.AdminRouter(runtimeConfig, opts.AdminRoutes)))
	})

	return r
}