package handlers

import (
	"encoding/json"
	"errors"
	"net/http"
	"testing"

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

// Tests for the read-only handlers (`internalListRuntimes`,
// `internalGetRuntime`). These bypass the service layer and read
// directly from `ports.RuntimeRecordStore` — see
// `rtmanager/docs/services.md` §18.

func TestListHandlerReturnsEmptyItemsForEmptyStore(t *testing.T) {
	t.Parallel()

	deps := Dependencies{RuntimeRecords: newFakeRuntimeRecords()}
	rec := drive(t, deps, http.MethodGet, "/api/v1/internal/runtimes", nil, nil)

	require.Equal(t, http.StatusOK, rec.Code)
	require.Equal(t, JSONContentType, rec.Header().Get("Content-Type"))

	var resp runtimesListResponse
	require.NoError(t, json.NewDecoder(rec.Body).Decode(&resp))
	require.NotNil(t, resp.Items, "items must never be nil")
	assert.Empty(t, resp.Items)
}

func TestListHandlerReturnsEveryStoredRecord(t *testing.T) {
	t.Parallel()

	store := newFakeRuntimeRecords()
	store.put(sampleRunningRecord(t))
	store.put(sampleStoppedRecord(t))

	rec := drive(t, Dependencies{RuntimeRecords: store}, http.MethodGet, "/api/v1/internal/runtimes", nil, nil)
	require.Equal(t, http.StatusOK, rec.Code)

	var resp runtimesListResponse
	require.NoError(t, json.NewDecoder(rec.Body).Decode(&resp))
	require.Len(t, resp.Items, 2)

	gotIDs := map[string]string{}
	for _, item := range resp.Items {
		gotIDs[item.GameID] = item.Status
	}
	assert.Equal(t, "running", gotIDs["game-test"])
	assert.Equal(t, "stopped", gotIDs["game-stopped"])
}

func TestListHandlerReturnsInternalErrorWhenStoreFails(t *testing.T) {
	t.Parallel()

	store := newFakeRuntimeRecords()
	store.listErr = errors.New("postgres exploded")

	rec := drive(t, Dependencies{RuntimeRecords: store}, http.MethodGet, "/api/v1/internal/runtimes", nil, nil)
	body := decodeErrorBody(t, rec, http.StatusInternalServerError)
	assert.Equal(t, "internal_error", body.Code)
}

func TestListHandlerReturnsInternalErrorWhenStoreNotWired(t *testing.T) {
	t.Parallel()

	rec := drive(t, Dependencies{}, http.MethodGet, "/api/v1/internal/runtimes", nil, nil)
	body := decodeErrorBody(t, rec, http.StatusInternalServerError)
	assert.Equal(t, "internal_error", body.Code)
}

func TestGetHandlerReturnsTheRecord(t *testing.T) {
	t.Parallel()

	store := newFakeRuntimeRecords()
	record := sampleRunningRecord(t)
	store.put(record)

	rec := drive(t, Dependencies{RuntimeRecords: store}, http.MethodGet, "/api/v1/internal/runtimes/game-test", nil, nil)
	resp := decodeRecordResponse(t, rec)
	assert.Equal(t, "game-test", resp.GameID)
	assert.Equal(t, "running", resp.Status)
	if assert.NotNil(t, resp.CurrentImageRef) {
		assert.Equal(t, "galaxy/game:v1.2.3", *resp.CurrentImageRef)
	}
}

func TestGetHandlerReturnsNotFoundForMissingRecord(t *testing.T) {
	t.Parallel()

	rec := drive(t, Dependencies{RuntimeRecords: newFakeRuntimeRecords()}, http.MethodGet, "/api/v1/internal/runtimes/game-missing", nil, nil)
	body := decodeErrorBody(t, rec, http.StatusNotFound)
	assert.Equal(t, "not_found", body.Code)
}

func TestGetHandlerReturnsInternalErrorWhenStoreFails(t *testing.T) {
	t.Parallel()

	store := newFakeRuntimeRecords()
	store.getErr = errors.New("transport blew up")

	rec := drive(t, Dependencies{RuntimeRecords: store}, http.MethodGet, "/api/v1/internal/runtimes/game-test", nil, nil)
	body := decodeErrorBody(t, rec, http.StatusInternalServerError)
	assert.Equal(t, "internal_error", body.Code)
}

func TestGetHandlerReturnsInternalErrorWhenStoreNotWired(t *testing.T) {
	t.Parallel()

	rec := drive(t, Dependencies{}, http.MethodGet, "/api/v1/internal/runtimes/game-test", nil, nil)
	body := decodeErrorBody(t, rec, http.StatusInternalServerError)
	assert.Equal(t, "internal_error", body.Code)
}