package aprs

import (
	"strings"
	"time"

	"git.maze.io/go/ham/util/maidenhead"
)

type Status struct {
	Time        time.Time
	Latitude    float64
	Longitude   float64
	BeamHeading int
	ERP         int
	Symbol      string
	Text        string
}

func (s Status) String() string {
	return s.Text
}

type statusReportDecoder struct{}

func (statusReportDecoder) CanDecode(frame Frame) bool {
	return frame.Raw.Type() == '>'
}

func (statusReportDecoder) Decode(frame Frame) (data Data, err error) {
	var (
		text   = string(frame.Raw[1:])
		status = new(Status)
	)
	if hasTimestamp(text) {
		if status.Time, text, err = parseTimestamp(text); err != nil {
			return
		}
	}

	if len(text) > 3 && text[len(text)-3] == '^' {
		var (
			h = text[len(text)-2]
			p = text[len(text)-1]
		)
		if h >= '0' && h <= '9' {
			status.BeamHeading = int(h-'0') * 10
		} else if h >= 'A' && h <= 'Z' {
			status.BeamHeading = 100 + int(h-'A')*10
		}
		if p >= '0' && p <= 'Z' {
			status.ERP = int(p-'0') * int(p-'0') * 10
		}
		text = text[:len(text)-3]
	}

	here := text
	if i := strings.IndexByte(here, ' '); i != -1 {
		here = here[:i]
	}
	switch len(here) {
	case 6:
		var point maidenhead.Point
		if point, err = maidenhead.ParseLocator(here[:4]); err != nil {
			return
		}
		status.Latitude = point.Latitude
		status.Longitude = point.Longitude
		status.Symbol = here[4:]
		if len(text) > 6 {
			text = text[7:]
		} else {
			text = text[6:]
		}
	case 8:
		var point maidenhead.Point
		if point, err = maidenhead.ParseLocator(here[:6]); err != nil {
			return
		}
		status.Latitude = point.Latitude
		status.Longitude = point.Longitude
		status.Symbol = here[6:]
		if len(text) > 8 {
			text = text[9:]
		} else {
			text = text[8:]
		}
	}

	status.Text = text
	return status, nil
}