package app

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

type ctxKey string

const userKey ctxKey = "user"

func (a *App) withAuth(next func(http.ResponseWriter, *http.Request, User)) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var u User
		if a.cfg.DevMode {
			u = User{Username: a.cfg.DemoUser, Email: a.cfg.DemoEmail}
		} else {
			u = User{Username: r.Header.Get(a.cfg.AuthHeaderUser), Email: r.Header.Get(a.cfg.AuthHeaderEmail)}
			if u.Username == "" {
				http.Error(w, "missing authenticated user header", http.StatusUnauthorized)
				return
			}
		}
		next(w, r.WithContext(context.WithValue(r.Context(), userKey, u)), u)
	}
}

func (a *App) withAPIUser(next func(http.ResponseWriter, *http.Request, User)) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if a.cfg.DevMode {
			u := User{Username: a.cfg.DemoUser, Email: a.cfg.DemoEmail}
			next(w, r.WithContext(context.WithValue(r.Context(), userKey, u)), u)
			return
		}
		authz := strings.TrimSpace(r.Header.Get("Authorization"))
		if !strings.HasPrefix(strings.ToLower(authz), "bearer ") {
			http.Error(w, "missing bearer token", http.StatusUnauthorized)
			return
		}
		token := strings.TrimSpace(authz[len("Bearer "):])
		u, err := a.validateBearerToken(token)
		if err != nil {
			http.Error(w, "invalid bearer token", http.StatusUnauthorized)
			return
		}
		next(w, r.WithContext(context.WithValue(r.Context(), userKey, u)), u)
	}
}

func loggingMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		lrw := &logResponseWriter{ResponseWriter: w, status: http.StatusOK}
		next.ServeHTTP(lrw, r)
		log.Printf("method=%s path=%s status=%d bytes=%d dur_ms=%d remote=%s ua=%q",
			r.Method,
			r.URL.Path,
			lrw.status,
			lrw.bytes,
			time.Since(start).Milliseconds(),
			r.RemoteAddr,
			r.UserAgent(),
		)
	})
}

type logResponseWriter struct {
	http.ResponseWriter
	status int
	bytes  int
}

func (l *logResponseWriter) WriteHeader(statusCode int) {
	l.status = statusCode
	l.ResponseWriter.WriteHeader(statusCode)
}

func (l *logResponseWriter) Write(b []byte) (int, error) {
	n, err := l.ResponseWriter.Write(b)
	l.bytes += n
	return n, err
}