package cassandra

import (
	"reflect"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"

	"github.com/gocql/gocql"
)

func TestGetCqlTag(t *testing.T) {
	monkey := &MonkeyEntity{
		// 為了測試用，欄位內容可以不給值
		ID:       gocql.TimeUUID(),
		Name:     "TestMonkey",
		UpdateAt: time.Now(),
		CreateAt: time.Now(),
	}

	tests := []struct {
		name        string
		model       interface{}
		fieldPtr    interface{}
		expected    string
		expectPanic bool
	}{
		{
			name:     "取得 Name 的 cql tag",
			model:    monkey,
			fieldPtr: &monkey.Name,
			expected: "name",
		},
		{
			name:     "取得 ID 的 cql tag",
			model:    monkey,
			fieldPtr: &monkey.ID,
			expected: "id",
		},
		{
			name:     "取得 UpdateAt 的 cql tag",
			model:    monkey,
			fieldPtr: &monkey.UpdateAt,
			expected: "update_at",
		},
		{
			name:     "取得 CreateAt 的 cql tag",
			model:    monkey,
			fieldPtr: &monkey.CreateAt,
			expected: "create_at",
		},
		{
			name:     "找不到對應欄位，回傳空字串",
			model:    monkey,
			fieldPtr: new(int), // 傳入與 MonkeyEntity 無關的欄位指標
			expected: "",
		},
		{
			name:     "非指向 struct 的 model，應該 panic",
			model:    MonkeyEntity{}, // 非指針
			fieldPtr: &monkey.Name,
			expected: "",
		},
	}

	for _, tt := range tests {
		tt := tt // 捕捉迴圈變數
		t.Run(tt.name, func(t *testing.T) {
			// 如果預期會 panic，則用 recover 進行驗證
			if tt.expectPanic {
				defer func() {
					if r := recover(); r == nil {
						t.Errorf("預期測試案例 %q 發生 panic，但實際並未 panic", tt.name)
					}
				}()
				_ = GetCqlTag(tt.model, tt.fieldPtr)
			} else {
				result := GetCqlTag(tt.model, tt.fieldPtr)
				if result != tt.expected {
					t.Errorf("測試案例 %q: 預期 %q, 但得到 %q", tt.name, tt.expected, result)
				}
			}
		})
	}
}

// -------------------- 測試函式 --------------------

// TestToSnakeCase 測試 toSnakeCase 函式
func TestToSnakeCase(t *testing.T) {
	testCases := []struct {
		input    string
		expected string
	}{
		{"CamelCase", "camel_case"},
		{"snake_case", "snake_case"},
		{"HttpServer", "http_server"},
		{"A", "a"},
		{"Already_Snake", "already__snake"}, // 依照實作，"Already_Snake" 轉換後會產生 double underscore
	}

	for _, tc := range testCases {
		t.Run(tc.input, func(t *testing.T) {
			result := toSnakeCase(tc.input)
			assert.Equal(t, tc.expected, result)
		})
	}
}

func TestIsZero(t *testing.T) {
	type testCase struct {
		name     string
		input    any
		expected bool
	}

	tests := []testCase{
		{"zero int", 0, true},
		{"non-zero int", 42, false},
		{"zero string", "", true},
		{"non-zero string", "hello", false},
		{"zero bool", false, true},
		{"non-zero bool", true, false},
		{"nil slice", []string(nil), true},
		{"empty slice", []string{}, false},
		{"nil pointer", (*int)(nil), true},
		{"non-nil pointer", new(int), false},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			v := reflect.ValueOf(tc.input)
			actual := isZero(v)
			if actual != tc.expected {
				t.Errorf("isZero(%v) = %v; want %v", tc.input, actual, tc.expected)
			}
		})
	}
}

func TestContains(t *testing.T) {
	type testCase struct {
		name     string
		list     []string
		target   string
		expected bool
	}

	tests := []testCase{
		{"contains first", []string{"a", "b", "c"}, "a", true},
		{"contains middle", []string{"a", "b", "c"}, "b", true},
		{"contains last", []string{"a", "b", "c"}, "c", true},
		{"not contains", []string{"a", "b", "c"}, "d", false},
		{"empty list", []string{}, "a", false},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			actual := contains(tc.list, tc.target)
			if actual != tc.expected {
				t.Errorf("contains(%v, %q) = %v; want %v", tc.list, tc.target, actual, tc.expected)
			}
		})
	}
}