package httputil

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
)

func TestDecodeJSONStrict(t *testing.T) {
	t.Run("valid", func(t *testing.T) {
		var got struct {
			Name string `json:"name"`
		}
		req := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(`{"name":"demo"}`))
		rr := httptest.NewRecorder()
		if !DecodeJSON(rr, req, &got) {
			t.Fatalf("DecodeJSON returned false: %s", rr.Body.String())
		}
		if got.Name != "demo" {
			t.Fatalf("unexpected decoded value: %#v", got)
		}
	})

	t.Run("unknown field", func(t *testing.T) {
		var got struct {
			Name string `json:"name"`
		}
		req := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(`{"name":"demo","extra":true}`))
		rr := httptest.NewRecorder()
		if DecodeJSON(rr, req, &got) {
			t.Fatal("DecodeJSON returned true for unknown field")
		}
		if rr.Code != http.StatusBadRequest {
			t.Fatalf("status = %d, want %d", rr.Code, http.StatusBadRequest)
		}
		if !strings.Contains(rr.Body.String(), "unknown field") {
			t.Fatalf("unexpected body: %s", rr.Body.String())
		}
	})

	t.Run("invalid json", func(t *testing.T) {
		var got map[string]string
		req := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(`{`))
		rr := httptest.NewRecorder()
		if DecodeJSON(rr, req, &got) {
			t.Fatal("DecodeJSON returned true for invalid JSON")
		}
		if rr.Code != http.StatusBadRequest {
			t.Fatalf("status = %d, want %d", rr.Code, http.StatusBadRequest)
		}
	})
}

func TestWriteJSONAndError(t *testing.T) {
	rr := httptest.NewRecorder()
	WriteJSON(rr, http.StatusCreated, map[string]string{"status": "ok"})
	if rr.Code != http.StatusCreated {
		t.Fatalf("status = %d", rr.Code)
	}
	if ct := rr.Header().Get("Content-Type"); ct != "application/json" {
		t.Fatalf("content-type = %q", ct)
	}
	var body map[string]string
	if err := json.Unmarshal(rr.Body.Bytes(), &body); err != nil {
		t.Fatal(err)
	}
	if body["status"] != "ok" {
		t.Fatalf("unexpected body: %#v", body)
	}

	rr = httptest.NewRecorder()
	WriteError(rr, http.StatusTeapot, "short and stout")
	if rr.Code != http.StatusTeapot {
		t.Fatalf("status = %d", rr.Code)
	}
	body = map[string]string{}
	if err := json.Unmarshal(rr.Body.Bytes(), &body); err != nil {
		t.Fatal(err)
	}
	if body["error"] != "short and stout" {
		t.Fatalf("unexpected error body: %#v", body)
	}
}