package meteo

import (
	"errors"
	"time"
)

type MeteoDataPerDay struct {
	MaxTemp    float32 `json:"max_temp"`
	MinTemp    float32 `json:"min_temp"`
	AvgTemp    float32 `json:"avg_temp"`
	Rainfall   float32 `json:"rainfall"`
	Cloudiness int     `json:"cloudiness"`
}

func (mtpd *MeteoDataPerDay) ConvertValue() {
	mtpd.MaxTemp = mtpd.MaxTemp*9/5 + 32
	mtpd.MinTemp = mtpd.MinTemp*9/5 + 32
	mtpd.AvgTemp = mtpd.AvgTemp*9/5 + 32
}

type Rolling7Data struct {
	AvgTemp       float32 `json:"avg_temp"`
	AvgCloudiness int     `json:"avg_cloudiness"`
	SumRainfall   float32 `json:"sum_rainfall"`
}

type MeteoData struct {
	Location string             `json:"location"`
	Unit     Unit               `json:"unit"`
	From     string             `json:"from"`
	Days     *[]MeteoDataPerDay `json:"days,omitempty"`
	Rolling7 *Rolling7Data      `json:"rolling7,omitempty"`
}

type Unit string

const (
	UnitC Unit = "C"
	UnitF Unit = "F"
)

type Agg string

const (
	AggDaily    Agg = "daily"
	AggRolling7 Agg = "rolling7"
)

type GetMeteoData struct {
	Location string
	Date     string
	Days     int
	Unit     Unit
	Agg      Agg
}

func (mt *GetMeteoData) Validate() error {
	if mt.Date == "" {
		mt.Date = time.Now().Format("2006-01-02")
	}

	if _, err := time.Parse("2006-01-02", mt.Date); err != nil {
		return ErrMissingOrInvalidDate
	}

	if mt.Days == 0 {
		mt.Days = 5
	}
	if mt.Days < 1 || mt.Days > 10 {
		return ErrInvalidDays
	}

	if mt.Unit == "" {
		mt.Unit = UnitC
	}

	if mt.Agg == "" {
		mt.Agg = AggDaily
	}

	return nil
}

var (
	ErrCityNotFound         = errors.New("city not found")
	ErrReadingData          = errors.New("error reading data")
	ErrMissingOrInvalidDate = errors.New("missing or invalid date")
	ErrInvalidDays          = errors.New("days must be between 1 and 10")
)