// Package results implements a helper that can be used to store the results of
// a Nagios, Centreon, Icinga... service monitoring plugin, and convert them to
// text which can be sent to the monitoring server.
package results // import nocternity.net/gomonop/pkg/results

import (
	"container/list"
	"fmt"
	"strings"

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

// Results represents the monitoring plugin's results, including its name,
// return status and message, additional lines of text, and performance
// data to be encoded in the output.
type Results struct {
	name      string
	status    status.Status
	message   string
	extraText *list.List
	perfData  map[string]*perfdata.PerfData
}

// New creates the plugin with `name` as its name and an unknown status.
func New(name string) *Results {
	p := new(Results)
	p.name = name
	p.status = status.StatusUnknown
	p.message = "no status set"
	p.perfData = make(map[string]*perfdata.PerfData)
	return p
}

// SetState sets the plugin's output code to `status` and its message to
// the specified `message`.
func (p *Results) SetState(status status.Status, message string) {
	p.status = status
	p.message = message
}

// AddLine adds the specified string to the extra output text buffer.
func (p *Results) AddLine(line string) {
	if p.extraText == nil {
		p.extraText = list.New()
	}
	p.extraText.PushBack(line)
}

// AddLinef formats the input and adds it to the text buffer.
func (p *Results) AddLinef(format string, data ...interface{}) {
	p.AddLine(fmt.Sprintf(format, data...))
}

// AddLines add the specified `lines` to the output text.
func (p *Results) AddLines(lines []string) {
	for _, line := range lines {
		p.AddLine(line)
	}
}

// AddPerfData adds performance data described by the "pd" argument to the
// output's performance data. If two performance data records are added for
// the same label, the program panics.
func (p *Results) AddPerfData(pd *perfdata.PerfData) {
	_, exists := p.perfData[pd.Label]
	if exists {
		panic("duplicate performance data " + pd.Label)
	}
	p.perfData[pd.Label] = pd
}

// String generates the plugin's text output from its name, status, text data
// and performance data.
func (p *Results) String() string {
	var strBuilder strings.Builder
	strBuilder.WriteString(p.name)
	strBuilder.WriteString(" ")
	strBuilder.WriteString(p.status.String())
	strBuilder.WriteString(": ")
	strBuilder.WriteString(p.message)
	if len(p.perfData) > 0 {
		strBuilder.WriteString(" | ")
		needSep := false
		for _, data := range p.perfData {
			if needSep {
				strBuilder.WriteString(", ")
			} else {
				needSep = true
			}
			strBuilder.WriteString(data.String())
		}
	}
	if p.extraText != nil {
		for em := p.extraText.Front(); em != nil; em = em.Next() {
			strBuilder.WriteString("\n")
			//nolint:forcetypeassert // we want to panic if this isn't a string
			strBuilder.WriteString(em.Value.(string))
		}
	}
	return strBuilder.String()
}

// ExitCode returns the plugin's exit code.
func (p *Results) ExitCode() int {
	return int(p.status)
}