package shared

import (
	"strconv"

	"github.com/gin-gonic/gin"
)

type PaginationInfo struct {
	Limit       int
	Offset      int
	Total       int
	TotalPages  int
	CurrentPage int
	HasNext     bool
	HasPrev     bool
}

func ParseQueryLimit(c *gin.Context) int {
	limit := 10 // default
	l, err := strconv.Atoi(c.Query("limit"))
	if err == nil {
		if l > 100 {
			limit = 100 // max limit default
		} else if l < 100 && l > 0 {
			limit = l
		}
	}

	return limit
}

func ParseQueryOffset(c *gin.Context) int {
	offset := 0
	o, err := strconv.Atoi(c.Query("offset"))
	if err == nil {
		if o > 0 {
			offset = o
		}
	}
	return offset
}

func (source *PaginationInfo) CalculatePagingInfo() *PaginationInfo {
	result := source

	result.TotalPages, result.CurrentPage = 0, 1
	if result.Limit > 0 {
		result.TotalPages = (result.Total + result.Limit - 1) / result.Limit
		result.CurrentPage = (result.Offset / result.Limit) + 1
	}

	result.HasNext = result.Offset+result.Limit < result.Total
	result.HasPrev = result.Offset > 0

	return result
}