/*
DESCRIPTION:
Any functions that are used internally by the use-case
*/
package patient

import (
	"fmt"
	e "simrs-vx/internal/domain/main-entities/patient"
	"strconv"

	dg "github.com/karincake/apem/db-gorm-pg"
)

func setData[T *e.CreateDto | *e.UpdateDto](input T, data *e.Patient) error {
	var inputSrc *e.CreateDto
	if inputT, ok := any(input).(*e.CreateDto); ok {
		inputSrc = inputT
	} else {
		inputTemp := any(input).(*e.UpdateDto)
		inputSrc = &inputTemp.CreateDto
	}

	if data.Id == 0 {
		medRecNum, err := GenerateNextMedicalRecordNumber()
		if err != nil {
			return err
		}
		data.Number = &medRecNum
	}

	data.Person_Id = inputSrc.Person_Id
	data.RegisteredAt = inputSrc.RegisteredAt
	data.Status_Code = inputSrc.Status_Code
	return nil
}

func GenerateNextMedicalRecordNumber() (string, error) {
	var last string
	err := dg.I.
		Table("\"Patient\"").
		Select("\"Number\"").
		Where("\"Number\" IS NOT NULL AND \"Number\" ~ '^[0-9]+$'"). // Only numeric strings
		Order("\"Number\"::bigint DESC").
		Limit(1).
		Scan(&last).Error
	if err != nil {
		return "", err
	}

	var nextInt int64
	var format string

	if last == "" {
		// No existing records, start with 10 digits
		nextInt = 1
		format = "%010d"
	} else {
		n, err := strconv.ParseInt(last, 10, 64)
		if err != nil {
			return "", err
		}
		nextInt = n + 1

		// Dynamically determine format based on existing number
		digitCount := len(last)

		// If the incremented number needs more digits, expand format
		nextStr := strconv.FormatInt(nextInt, 10)
		if len(nextStr) > digitCount {
			digitCount = len(nextStr)
		}

		// Ensure minimum 10 digits as per requirement
		if digitCount < 10 {
			digitCount = 10
		}

		format = fmt.Sprintf("%%0%dd", digitCount)
	}

	return fmt.Sprintf(format, nextInt), nil
}