package tests

import (
	"bytes"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"testing"
	"time"

	"gitea.kleinsense.nl/DariusKlein/kleinTodo/common"
	"gitea.kleinsense.nl/DariusKlein/kleinTodo/server/handler"
	"github.com/google/uuid"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestIntegrationSync(t *testing.T) {
	// 1. Setup Environment
	tempDir, err := os.MkdirTemp("", "todo-test-*")
	require.NoError(t, err)
	defer os.RemoveAll(tempDir)

	// Override storage path for BoltStore by setting HOME or XDG_CONFIG_HOME
	// BoltStore uses os.UserConfigDir() which looks at XDG_CONFIG_HOME on Linux
	os.Setenv("XDG_CONFIG_HOME", tempDir)
	os.Setenv("JWT_SECRET", "test-secret-123")

	// 2. Initialize Server
	mux := http.NewServeMux()
	mux.HandleFunc("POST /register", handler.RegisterHandler)
	mux.HandleFunc("POST /login", handler.LoginHandler)
	mux.HandleFunc("POST /sync", handler.SyncHandler)
	ts := httptest.NewServer(mux)
	defer ts.Close()

	client := ts.Client()
	username := "testuser"
	password := "testpass"

	// 3. Register User
	regPayload, _ := json.Marshal(common.Credentials{Username: username, Password: password})
	resp, err := client.Post(ts.URL+"/register", "application/json", bytes.NewBuffer(regPayload))
	require.NoError(t, err)
	assert.Equal(t, http.StatusOK, resp.StatusCode)

	// 4. Login and Get Token
	resp, err = client.Post(ts.URL+"/login", "application/json", bytes.NewBuffer(regPayload))
	require.NoError(t, err)
	assert.Equal(t, http.StatusOK, resp.StatusCode)
	token := resp.Header.Get(common.AuthHeader)
	require.NotEmpty(t, token)

	// 5. Create Local Todos
	store, err := common.GetTodoDataStore()
	require.NoError(t, err)
	defer store.Close()

	todo1 := common.Todo{
		Id:           uuid.New().String(),
		Name:         "Task 1",
		Description:  "Desc 1",
		Status:       common.NotStarted,
		Owner:        username,
		LastModified: time.Now().UTC(),
	}
	todo2 := common.Todo{
		Id:           uuid.New().String(),
		Name:         "Task 2",
		Description:  "Desc 2",
		Status:       common.WIP,
		Owner:        username,
		LastModified: time.Now().UTC(),
	}

	err = todo1.Store(store, username)
	require.NoError(t, err)
	err = todo2.Store(store, username)
	require.NoError(t, err)

	// 6. Sync to Server
	localTodos := store.GetTodoList(username, true)
	syncReq := common.TodoList{Todos: localTodos}
	syncPayload, _ := json.Marshal(syncReq)

	req, _ := http.NewRequest("POST", ts.URL+"/sync", bytes.NewBuffer(syncPayload))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set(common.AuthHeader, "Bearer "+token)

	resp, err = client.Do(req)
	require.NoError(t, err)
	assert.Equal(t, http.StatusOK, resp.StatusCode)

	var syncResp common.SyncResponse
	err = json.NewDecoder(resp.Body).Decode(&syncResp)
	require.NoError(t, err)
	resp.Body.Close()

	// Verify both todos are in sync response
	assert.Len(t, syncResp.SyncedTodos, 2)
	assert.Empty(t, syncResp.MisMatchingTodos)

	// 7. Verify Server State (By syncing again with empty local)
	emptySyncReq := common.TodoList{Todos: []common.Todo{}}
	emptySyncPayload, _ := json.Marshal(emptySyncReq)
	req, _ = http.NewRequest("POST", ts.URL+"/sync", bytes.NewBuffer(emptySyncPayload))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set(common.AuthHeader, "Bearer "+token)

	resp, err = client.Do(req)
	require.NoError(t, err)
	assert.Equal(t, http.StatusOK, resp.StatusCode)

	err = json.NewDecoder(resp.Body).Decode(&syncResp)
	require.NoError(t, err)
	resp.Body.Close()

	assert.Len(t, syncResp.SyncedTodos, 2, "Server should have kept the synced todos")

	// 8. Test Pulling from Server (New Client)
	// Create another temporary directory for a different client
	client2TempDir, err := os.MkdirTemp("", "todo-test-client2-*")
	require.NoError(t, err)
	defer os.RemoveAll(client2TempDir)

	// Since common.GetTodoDataStore() uses sync.Once, we can't easily get a new database in the same process
	// BUT for this test, we can just use GetCustomDataStore("todo2.db") if it was public,
	// however it seems we can just check if the server returns the data when requested.

	req, _ = http.NewRequest("POST", ts.URL+"/sync", bytes.NewBuffer(emptySyncPayload))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set(common.AuthHeader, "Bearer "+token)

	resp, err = client.Do(req)
	require.NoError(t, err)
	assert.Equal(t, http.StatusOK, resp.StatusCode)

	err = json.NewDecoder(resp.Body).Decode(&syncResp)
	require.NoError(t, err)
	resp.Body.Close()

	assert.Len(t, syncResp.SyncedTodos, 2, "Server should return the 2 todos for a sync request")
}