package file

import (
	"io/fs"
	"os"
	"path/filepath"
	"time"

	"github.com/asaskevich/govalidator"
	"github.com/juju/errors"
)

// ConfigStruct is the configuration for File Provider.
type ConfigStruct struct {
	Filename      string  `yaml:"filename"`
	Rotate        bool    `yaml:"rotate"`
	RotateTime    *string `yaml:"rotate_time"`
	RotateMaxAge  *string `yaml:"rotate_max_age"`
	RotateMaxFile *int    `yaml:"rotate_max_file"`
}

// IsValid will check that the File configuration is valid.
func (c *ConfigStruct) IsValid() error {

	if c.Filename == "" {
		return errors.NotValidf("Path is empty in File configuration")
	} else if isValid, _ := govalidator.IsFilePath(c.Filename); !isValid {
		return errors.NotValidf("Path is invalid in File configuration")
	}

	dir := filepath.Dir(c.Filename)

	if _, err := os.Stat(dir); err != nil {
		if errors.Is(err, fs.ErrPermission) {
			return errors.NewForbidden(err, "Filename directory is not readeable in File configuration")
		} else if errors.Is(err, fs.ErrNotExist) {
			return errors.NewNotFound(err, "Filename directory does not exist in File configuration")
		} else {
			return errors.Trace(err)
		}
	}

	if c.Rotate {

		if c.RotateTime == nil || *c.RotateTime == "" {
			return errors.NotValidf("rotate_time cannot be null or an empty string in File configuration")
		} else if _, err := time.ParseDuration(*c.RotateTime); err != nil {
			return errors.NewNotValid(err, "rotate_time contain an invalid duration in File configuration")
		}

		if c.RotateMaxFile != nil && *c.RotateMaxFile <= 0 {
			return errors.NotValidf("rotate_max_file cannot be negative or 0 in File configuration")
		}

		if c.RotateMaxAge != nil && *c.RotateMaxAge == "" {
			return errors.NotValidf("rotate_max_age cannot be an empty string in File configuration")
		} else if c.RotateMaxAge != nil {
			if _, err := time.ParseDuration(*c.RotateMaxAge); err != nil {
				return errors.NewNotValid(err, "rotate_max_age contain an invalid duration in File configuration")
			}
		}

		if c.RotateMaxFile != nil && c.RotateMaxAge != nil {
			return errors.NotValidf("rotate_max_age and rotate_max_file cannot be defined at the same time in File configuration")
		}
	}
	return nil
}