package pagination

import (
	"net/http/httptest"
	"testing"

	"github.com/gin-gonic/gin"
	"github.com/stretchr/testify/assert"
)

func TestParseParams_Defaults(t *testing.T) {
	gin.SetMode(gin.TestMode)
	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = httptest.NewRequest("GET", "/?page=&limit=", nil)

	params, err := ParseParams(c)
	assert.Nil(t, err)
	assert.Equal(t, 1, params.Page)
	assert.Equal(t, DefaultPageSize, params.Limit)
}

func TestParseParams_Explicit(t *testing.T) {
	gin.SetMode(gin.TestMode)
	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = httptest.NewRequest("GET", "/?page=3&limit=50", nil)

	params, err := ParseParams(c)
	assert.Nil(t, err)
	assert.Equal(t, 3, params.Page)
	assert.Equal(t, 50, params.Limit)
}

func TestParseParams_ExplicitInvalidPage(t *testing.T) {
	// Explicit page=0 should still default to 1 (lenient) - we only reject limit > 100
	gin.SetMode(gin.TestMode)
	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = httptest.NewRequest("GET", "/?page=0&limit=20", nil)

	params, err := ParseParams(c)
	assert.Nil(t, err)
	assert.Equal(t, 1, params.Page) // normalized to 1
}

func TestParseParams_LimitTooHigh(t *testing.T) {
	gin.SetMode(gin.TestMode)
	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = httptest.NewRequest("GET", "/?page=1&limit=150", nil)

	_, err := ParseParams(c)
	assert.NotNil(t, err)
}

func TestParams_Offset(t *testing.T) {
	p := Params{Page: 1, Limit: 20}
	assert.Equal(t, 0, p.Offset())

	p = Params{Page: 2, Limit: 20}
	assert.Equal(t, 20, p.Offset())

	p = Params{Page: 5, Limit: 10}
	assert.Equal(t, 40, p.Offset())
}

func TestBuildMeta(t *testing.T) {
	meta := BuildMeta(1, 20, 150)
	assert.Equal(t, 1, meta.Page)
	assert.Equal(t, 20, meta.Limit)
	assert.Equal(t, int64(150), meta.Total)
	assert.Equal(t, 8, meta.TotalPages)
}