package invited_code

import (
	"testing"

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

// 測試 ConvertUseCase 的功能
func TestConverter(t *testing.T) {
	tests := []struct {
		name      string
		id        int64
		base      int
		length    int
		wantCode  string
		wantError bool
	}{
		{
			name:      "Test Case 1: Valid ID 1000000",
			id:        10000000,
			base:      10,
			length:    7,
			wantCode:  "DOOOOOOO",
			wantError: false,
		},
		{
			name:      "Test Case 2: Valid ID 12345678",
			id:        12345678,
			base:      10,
			length:    8,
			wantCode:  "DWXYGBCH",
			wantError: false,
		},
		{
			name:      "Test Case 3: Valid ID 98765432",
			id:        98765432,
			base:      10,
			length:    8,
			wantCode:  "EHCBGYXW",
			wantError: false,
		},
		{
			name:      "Test Case 4: ID too large",
			id:        10000000000000001, // ID 超過界限
			base:      10,
			length:    8,
			wantCode:  "",
			wantError: true,
		},
	}

	converter := MustConverter(10, 8, ConvertTable)

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			code, err := converter.EncodeFromNum(tt.id)

			if tt.wantError {
				assert.Error(t, err)
			} else {
				assert.NoError(t, err)
				assert.Equal(t, tt.wantCode, code)
			}

			if !tt.wantError {
				// 測試解碼
				decodedID, err := converter.DecodeFromCode(code)
				assert.NoError(t, err)
				assert.Equal(t, tt.id, decodedID)
			}
		})
	}
}

func TestDecodeFromCode(t *testing.T) {
	converter := MustConverter(10, 8, ConvertTable)

	tests := []struct {
		name      string
		code      string
		wantID    int64
		wantError bool
	}{
		{
			name:      "Decode valid code 1",
			code:      "DOOOOOOO", // 對應於 id 10000000
			wantID:    10000000,
			wantError: false,
		},
		{
			name:      "Decode valid code 2",
			code:      "DWXYGBCH", // 對應於 id 12345678
			wantID:    12345678,
			wantError: false,
		},
		{
			name:      "Decode valid code 3",
			code:      "EHCBGYXW", // 對應於 id 98765432
			wantID:    98765432,
			wantError: false,
		},
		{
			name:      "Decode invalid code with character not in table",
			code:      "UWOXZZZ", // 包含 ZZZ，不在轉換表中
			wantID:    0,
			wantError: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result, err := converter.DecodeFromCode(tt.code)

			if tt.wantError {
				assert.Error(t, err)
				assert.Equal(t, int64(0), result)
			} else {
				assert.NoError(t, err)
				assert.Equal(t, tt.wantID, result)
			}
		})
	}
}