package check

import (
	"regexp"
	"strconv"
	"strings"
)

//DfChecker df command implementation of AdvancedChecker
type DfChecker struct {
	CliChecker
	pourcentRegexMatcher *regexp.Regexp
}

type DfOut []DfOutLine
type DfOutLine struct {
	Filesystem,
	Size,
	Used,
	Available string
	PourcentUsed int
	Mounted      string
}

//NewDfChecker build new checker for df command
func NewDfChecker(alertingMessage string, command ...string) AdvancedChecker {

	return &DfChecker{
		CliChecker: CliChecker{
			alertingMessage: alertingMessage,
			command:         command,
		},
		pourcentRegexMatcher: regexp.MustCompile(`(?P<value>.*)%`),
	}
}

//DfParser parse df stdout
func (dc *DfChecker) Parse(stdout string) (interface{}, error) {
	var dfOut DfOut

	for _, line := range strings.Split(stdout, "\n")[1:] {
		if strings.TrimSpace(line) == "" {
			continue
		}

		var cleanedColumns []string
		for _, col := range strings.Split(line, " ") {
			if v := strings.TrimSpace(col); v != "" {
				cleanedColumns = append(cleanedColumns, v)
			}
		}

		valueIndex := dc.pourcentRegexMatcher.SubexpIndex("value")
		v, err := strconv.Atoi(dc.pourcentRegexMatcher.FindStringSubmatch(cleanedColumns[4])[valueIndex])
		if err != nil {
			return dfOut, err
		}
		// extract pourcent used from columns
		dfOut = append(dfOut, DfOutLine{
			Filesystem:   cleanedColumns[0],
			Size:         cleanedColumns[1],
			Used:         cleanedColumns[2],
			Available:    cleanedColumns[3],
			PourcentUsed: v,
			Mounted:      cleanedColumns[len(cleanedColumns)-1],
		})
	}
	return dfOut, nil
}

func FileSystemChecker(fileSystemName string, criticalPourcent int, dfOut DfOut) bool {
	for _, line := range dfOut {
		if line.Filesystem == fileSystemName {
			if line.PourcentUsed > criticalPourcent {
				return true
			}
		}
	}
	return false
}