package middleware

import (
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestResponseWriter_WriteHeader(t *testing.T) {
	rec := httptest.NewRecorder()
	rw := &responseWriter{
		ResponseWriter: rec,
		status:         http.StatusOK,
	}

	// First call should set status
	rw.WriteHeader(http.StatusNotFound)
	if rw.status != http.StatusNotFound {
		t.Errorf("status = %d, want %d", rw.status, http.StatusNotFound)
	}
	if !rw.wroteHeader {
		t.Error("wroteHeader should be true after WriteHeader")
	}

	// Second call should be ignored
	rw.WriteHeader(http.StatusInternalServerError)
	if rw.status != http.StatusNotFound {
		t.Errorf("status = %d, want %d (should not change)", rw.status, http.StatusNotFound)
	}
}

func TestResponseWriter_Write(t *testing.T) {
	rec := httptest.NewRecorder()
	rw := &responseWriter{
		ResponseWriter: rec,
		status:         http.StatusOK,
	}

	// Write should set default status if not set
	n, err := rw.Write([]byte("Hello"))
	if err != nil {
		t.Errorf("Write() error = %v", err)
	}
	if n != 5 {
		t.Errorf("Write() n = %d, want 5", n)
	}
	if rw.written != 5 {
		t.Errorf("written = %d, want 5", rw.written)
	}
	if !rw.wroteHeader {
		t.Error("wroteHeader should be true after Write")
	}
	if rw.status != http.StatusOK {
		t.Errorf("status = %d, want %d", rw.status, http.StatusOK)
	}

	// Write more
	n, err = rw.Write([]byte(" World"))
	if err != nil {
		t.Errorf("Write() error = %v", err)
	}
	if n != 6 {
		t.Errorf("Write() n = %d, want 6", n)
	}
	if rw.written != 11 {
		t.Errorf("written = %d, want 11", rw.written)
	}
}

func TestResponseWriter_WriteWithExplicitStatus(t *testing.T) {
	rec := httptest.NewRecorder()
	rw := &responseWriter{
		ResponseWriter: rec,
		status:         http.StatusOK,
	}

	// Set status first
	rw.WriteHeader(http.StatusCreated)

	// Write should not change status
	_, _ = rw.Write([]byte("Created"))
	if rw.status != http.StatusCreated {
		t.Errorf("status = %d, want %d", rw.status, http.StatusCreated)
	}
}

func TestLogger(t *testing.T) {
	t.Run("Logs successful request", func(t *testing.T) {
		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusOK)
			_, _ = w.Write([]byte("OK"))
		})

		logged := Logger(handler)

		req := httptest.NewRequest(http.MethodGet, "/test", nil)
		rec := httptest.NewRecorder()

		logged.ServeHTTP(rec, req)

		if rec.Code != http.StatusOK {
			t.Errorf("Code = %d, want %d", rec.Code, http.StatusOK)
		}
		if rec.Body.String() != "OK" {
			t.Errorf("Body = %q, want %q", rec.Body.String(), "OK")
		}
	})

	t.Run("Logs error response", func(t *testing.T) {
		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			http.Error(w, "Not Found", http.StatusNotFound)
		})

		logged := Logger(handler)

		req := httptest.NewRequest(http.MethodGet, "/notfound", nil)
		rec := httptest.NewRecorder()

		logged.ServeHTTP(rec, req)

		if rec.Code != http.StatusNotFound {
			t.Errorf("Code = %d, want %d", rec.Code, http.StatusNotFound)
		}
	})

	t.Run("Handles POST request", func(t *testing.T) {
		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusCreated)
		})

		logged := Logger(handler)

		req := httptest.NewRequest(http.MethodPost, "/create", nil)
		rec := httptest.NewRecorder()

		logged.ServeHTTP(rec, req)

		if rec.Code != http.StatusCreated {
			t.Errorf("Code = %d, want %d", rec.Code, http.StatusCreated)
		}
	})

	t.Run("Handles request with no explicit status", func(t *testing.T) {
		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// Just write body without explicit status
			_, _ = w.Write([]byte("Implicit OK"))
		})

		logged := Logger(handler)

		req := httptest.NewRequest(http.MethodGet, "/implicit", nil)
		rec := httptest.NewRecorder()

		logged.ServeHTTP(rec, req)

		// Default status should be 200
		if rec.Code != http.StatusOK {
			t.Errorf("Code = %d, want %d", rec.Code, http.StatusOK)
		}
	})
}