// Package `perfdata` provides representations for a monitoring plugin's
// performance data.
package perfdata // import nocternity.net/gomonop/pkg/perfdata

import (
	"strconv"
	"strings"

	"nocternity.net/gomonop/pkg/status"
)

// Performance data, including a label, units, a value, warning/critical
// ranges and min/max boundaries.
type PerfData struct {
	Label      string
	units      UnitOfMeasurement
	bits       perfDataBits
	value      string
	warn, crit Range
	min, max   string
}

// Create performance data using the specified label and units.
func New(label string, units UnitOfMeasurement, value string) *PerfData {
	if value != "" && !valueCheck.MatchString(value) {
		panic("invalid value")
	}
	pdRange := &PerfData{}
	pdRange.Label = label
	pdRange.units = units
	if value == "" {
		pdRange.value = "U"
	} else {
		pdRange.value = value
	}
	return pdRange
}

// Set the warning range for the performance data record.
func (d *PerfData) SetWarn(r *Range) {
	if r == nil {
		d.bits &^= PDatWarn
	} else {
		d.warn = *r
		d.bits |= PDatWarn
	}
}

// Set the critical range for the performance data record.
func (d *PerfData) SetCrit(r *Range) {
	if r == nil {
		d.bits &^= PDatCrit
	} else {
		d.crit = *r
		d.bits |= PDatCrit
	}
}

// Set the performance data's minimal value.
func (d *PerfData) SetMin(min string) {
	if !valueCheck.MatchString(min) {
		panic("invalid value")
	}
	d.min = min
	d.bits |= PDatMin
}

// Set the performance data's maximal value.
func (d *PerfData) SetMax(max string) {
	if !valueCheck.MatchString(max) {
		panic("invalid value")
	}
	d.max = max
	d.bits |= PDatMax
}

// Check the performance data's value against its configured ranges.
func (d *PerfData) GetStatus() status.Status {
	value, err := strconv.ParseFloat(d.value, 64)
	if err != nil {
		return status.StatusUnknown
	}

	if d.bits&PDatCrit != 0 && d.crit.Contains(value) {
		return status.StatusCritical
	}
	if d.bits&PDatWarn != 0 && d.warn.Contains(value) {
		return status.StatusWarning
	}

	return status.StatusOK
}

// Converts performance data to a string which may be read by the monitoring
// system.
func (d *PerfData) String() string {
	var strBuilder strings.Builder
	needsQuotes := strings.ContainsAny(d.Label, " '=\"")
	if needsQuotes {
		strBuilder.WriteRune('\'')
	}
	strBuilder.WriteString(strings.ReplaceAll(d.Label, "'", "''"))
	if needsQuotes {
		strBuilder.WriteRune('\'')
	}
	strBuilder.WriteRune('=')
	strBuilder.WriteString(d.value)
	strBuilder.WriteString(d.units.String())
	strBuilder.WriteRune(';')
	if d.bits&PDatWarn != 0 {
		strBuilder.WriteString(d.warn.String())
	}
	strBuilder.WriteRune(';')
	if d.bits&PDatCrit != 0 {
		strBuilder.WriteString(d.crit.String())
	}
	strBuilder.WriteRune(';')
	if d.bits&PDatMin != 0 {
		strBuilder.WriteString(d.min)
	}
	strBuilder.WriteRune(';')
	if d.bits&PDatMax != 0 {
		strBuilder.WriteString(d.max)
	}

	return strBuilder.String()
}