package main

import (
	"bufio"
	"os"
	"strconv"
)

func LoadData(path string) []DataEntry {
	readFile, err := os.Open(path)
	checkErr(err)
	fileScanner := bufio.NewScanner(readFile)
	fileScanner.Split(bufio.ScanLines)
	var fileLines []string
	for fileScanner.Scan() {
		fileLines = append(fileLines, fileScanner.Text())
	}
	err = readFile.Close()
	checkErr(err)
	var data []DataEntry
	lastData := 0
	for _, line := range fileLines {
		toInt, err := strconv.Atoi(line)
		status := Nothing
		checkErr(err)
		switch {
		case lastData == 0:
			status = Nothing
		case lastData < toInt:
			status = Increased
		case lastData > toInt:
			status = Decreased
		case lastData == toInt:
			status = Equal
		}
		lastData = toInt
		data = append(data, DataEntry{
			Value:  toInt,
			Status: status,
		})
	}
	return data
}

type Status int

const (
	Nothing Status = iota
	Decreased
	Increased
	Equal
)

func (s Status) String() string {
	switch s {
	case Nothing:
		return "N/A - no previous measurement"
	case Increased:
		return "increased"
	case Decreased:
		return "decreased"
	case Equal:
		return "equal"
	default:
		return ""
	}
}

type DataEntry struct {
	Value  int
	Status Status
}