package http

import (
	"strings"

	"github.com/gofiber/fiber/v3"

	"knowfoolery/backend/services/gateway-service/internal/infra/proxy"
	"knowfoolery/backend/services/gateway-service/internal/infra/routing"
)

// Options defines route wiring dependencies.
type Options struct {
	PublicPrefix string
	Upstreams    routing.Upstreams
	Proxy        *proxy.ReverseProxy

	AuthMiddleware      fiber.Handler
	RateLimitMiddleware fiber.Handler
}

// RegisterRoutes registers gateway forwarding routes.
func RegisterRoutes(app *fiber.App, opts Options) {
	prefix := normalizePrefix(opts.PublicPrefix)
	api := app.Group(prefix)

	if opts.RateLimitMiddleware != nil {
		api.Use(opts.RateLimitMiddleware)
	}
	if opts.AuthMiddleware != nil {
		api.Use(opts.AuthMiddleware)
	}

	// Question bank public routes.
	api.Post("/questions/random", forward(opts, opts.Upstreams.QuestionBank))
	api.Get("/questions/:id", forward(opts, opts.Upstreams.QuestionBank))
	api.Post("/questions/:id/validate-answer", forward(opts, opts.Upstreams.QuestionBank))

	// Session routes.
	api.All("/sessions", forward(opts, opts.Upstreams.GameSession))
	api.All("/sessions/*", forward(opts, opts.Upstreams.GameSession))

	// User routes.
	api.All("/users", forward(opts, opts.Upstreams.User))
	api.All("/users/*", forward(opts, opts.Upstreams.User))

	// Leaderboard routes.
	api.Get("/leaderboard/top10", forward(opts, opts.Upstreams.Leaderboard))
	api.Get("/leaderboard/stats", forward(opts, opts.Upstreams.Leaderboard))
	api.Get("/leaderboard/players/:id", forward(opts, opts.Upstreams.Leaderboard))
	api.Post("/leaderboard/update", forward(opts, opts.Upstreams.Leaderboard))

	// Admin passthrough routes.
	api.All("/admin/questions", forward(opts, opts.Upstreams.QuestionBank))
	api.All("/admin/questions/*", forward(opts, opts.Upstreams.QuestionBank))
	api.All("/admin/themes", forward(opts, opts.Upstreams.QuestionBank))
	api.All("/admin/themes/*", forward(opts, opts.Upstreams.QuestionBank))
	api.All("/admin/users", forward(opts, opts.Upstreams.User))
	api.All("/admin/users/*", forward(opts, opts.Upstreams.User))
	api.Post("/admin/auth", forward(opts, opts.Upstreams.Admin))
	api.Get("/admin/dashboard", forward(opts, opts.Upstreams.Admin))
	api.Get("/admin/audit", forward(opts, opts.Upstreams.Admin))
}

func forward(opts Options, upstream string) fiber.Handler {
	return func(c fiber.Ctx) error {
		targetPath := strings.TrimPrefix(c.Path(), normalizePrefix(opts.PublicPrefix))
		if targetPath == "" {
			targetPath = "/"
		}
		return opts.Proxy.Forward(c, upstream, targetPath)
	}
}

func normalizePrefix(raw string) string {
	prefix := strings.TrimSpace(raw)
	if prefix == "" {
		prefix = "/api/v1"
	}
	if !strings.HasPrefix(prefix, "/") {
		prefix = "/" + prefix
	}
	return strings.TrimRight(prefix, "/")
}