package originclient

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"sync/atomic"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func testConfig(url string) Config {
	return Config{
		URL:           url,
		ServiceKey:    "test-key",
		Type:          "icy2",
		Version:       "v1.0.0",
		Name:          "icy2-test",
		Site:          "Test Site",
		Environment:   "test",
		IntervalHours: 24,
		InstallID:     "test-install-id",
	}
}

func TestNew_RequiresFields(t *testing.T) {
	_, err := New(Config{})
	assert.Error(t, err)
}

func TestNew_AppliesDefaults(t *testing.T) {
	c, err := New(Config{ServiceKey: "k", Type: "t", Version: "v", Name: "n", InstallID: "id"})
	require.NoError(t, err)
	assert.Equal(t, DefaultURL, c.cfg.URL)
	assert.Equal(t, "go", c.cfg.AppType)
	assert.Equal(t, DefaultIntervalHours, c.cfg.IntervalHours)
	assert.Equal(t, "id", c.installID)
}

func TestBuildPayload(t *testing.T) {
	c, err := New(testConfig("https://example.invalid/checkin"))
	require.NoError(t, err)

	payload := c.buildPayload()

	assert.Equal(t, "icy2", payload.Type)
	assert.Equal(t, "go", payload.AppType)
	assert.Equal(t, "v1.0.0", payload.Version)
	assert.Equal(t, "icy2-test", payload.Name)
	assert.Equal(t, "Test Site", payload.Site)
	assert.Equal(t, "test", payload.Environment)
	assert.Equal(t, "test-install-id", payload.UniqueInstallID)
}

func TestCheckinOnce_Success(t *testing.T) {
	var gotKey string
	var gotBody Payload
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gotKey = r.Header.Get("X-Origin-Service-Key")
		require.NoError(t, json.NewDecoder(r.Body).Decode(&gotBody))
		w.WriteHeader(http.StatusOK)
		_ = json.NewEncoder(w).Encode(Response{
			Success:           true,
			ServiceInstanceID: 42,
			UniqueInstallID:   gotBody.UniqueInstallID,
			Status:            "provisioning",
			PingedAt:          "2026-08-01T00:00:00Z",
		})
	}))
	defer server.Close()

	c, err := New(testConfig(server.URL))
	require.NoError(t, err)

	resp, err := c.CheckinOnce(t.Context())
	require.NoError(t, err)

	assert.Equal(t, "test-key", gotKey)
	assert.Equal(t, "icy2", gotBody.Type)
	assert.Equal(t, "icy2-test", gotBody.Name)
	assert.Equal(t, "test-install-id", gotBody.UniqueInstallID)
	assert.True(t, resp.Success)
	assert.Equal(t, int64(42), resp.ServiceInstanceID)
}

func TestCheckinOnce_ServerErrorReturnsError(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	}))
	defer server.Close()

	c, err := New(testConfig(server.URL))
	require.NoError(t, err)

	resp, err := c.CheckinOnce(t.Context())
	assert.Error(t, err)
	assert.Nil(t, resp)
}

func TestCheckinOnce_UnreachableDoesNotPanic(t *testing.T) {
	c, err := New(testConfig("http://127.0.0.1:1"))
	require.NoError(t, err)

	assert.NotPanics(t, func() {
		_, _ = c.CheckinOnce(t.Context())
	})
}

func TestCheckinOnce_LogsOnFailure(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	}))
	defer server.Close()

	cfg := testConfig(server.URL)
	var warned bool
	cfg.Logger = LoggerFunc(func(msg string, err error) { warned = true })

	c, err := New(cfg)
	require.NoError(t, err)

	_, _ = c.CheckinOnce(t.Context())
	assert.True(t, warned)
}

func TestRun_ChecksInImmediatelyThenStopsOnContextDone(t *testing.T) {
	var calls atomic.Int32
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		calls.Add(1)
		w.WriteHeader(http.StatusOK)
		_ = json.NewEncoder(w).Encode(Response{Success: true})
	}))
	defer server.Close()

	c, err := New(testConfig(server.URL))
	require.NoError(t, err)

	ctx, cancel := context.WithTimeout(t.Context(), 200*time.Millisecond)
	defer cancel()

	c.Run(ctx)

	assert.Equal(t, int32(1), calls.Load())
}