package middleware

import (
	"context"
	"net/http"
	"strings"

	"aggios-app/backend/internal/repository"
)

type tenantContextKey string

const TenantIDKey tenantContextKey = "tenantID"
const SubdomainKey tenantContextKey = "subdomain"

// TenantDetector detects tenant from subdomain
func TenantDetector(tenantRepo *repository.TenantRepository) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			host := r.Host
			
			// Extract subdomain
			// Examples:
			// - agencia-xyz.localhost -> agencia-xyz
			// - agencia-xyz.aggios.app -> agencia-xyz
			// - dash.localhost -> dash (master admin)
			// - localhost -> (institutional site)
			
			parts := strings.Split(host, ".")
			var subdomain string
			
			if len(parts) >= 2 {
				// Has subdomain
				subdomain = parts[0]
				
				// Remove port if present
				if strings.Contains(subdomain, ":") {
					subdomain = strings.Split(subdomain, ":")[0]
				}
			}
			
			// Add subdomain to context
			ctx := context.WithValue(r.Context(), SubdomainKey, subdomain)
			
			// If subdomain is not empty and not "dash" or "api", try to find tenant
			if subdomain != "" && subdomain != "dash" && subdomain != "api" && subdomain != "localhost" {
				tenant, err := tenantRepo.FindBySubdomain(subdomain)
				if err == nil && tenant != nil {
					ctx = context.WithValue(ctx, TenantIDKey, tenant.ID.String())
				}
			}
			
			next.ServeHTTP(w, r.WithContext(ctx))
		})
	}
}