// Package notifyrender owns the subject/body templates used by both the
// legacy sender (internal/sender) and the worker-driven notification
// producer (internal/notifier). It is a leaf package so the notifier package
// can pre-render notification content for the worker without importing the
// sender package, which would otherwise create an import cycle (sender's
// tests already import notifier to drive the legacy loop).
package notifyrender

import (
	"bytes"
	"strings"
	"time"

	"github.com/russross/blackfriday/v2"

	"rocketgit.ru/rsmon/worker/app/models"
)

const (
	stateDown = "down"
	stateUp   = "up"
	stateTest = "test"
	stateExp  = "exp"
)

// GetContent pre-renders subject + bodies for one Message using the same
// templates the legacy sender used to apply at delivery time. The result is
// what the worker binary consumes directly so it does not need access to
// Message/Event rows, workdays, or NotificationDayStart logic on the data plane.
//
// Returns the four bodies (subject, text, markdown, html). The caller is
// responsible for passing them through to the worker task payload.
func GetContent(message *models.Message, tn time.Time) (bytes.Buffer, bytes.Buffer, bytes.Buffer, bytes.Buffer) {
	var subject, textBody, markdownBody, htmlBody bytes.Buffer

	if message.Kind == stateTest {
		subject.WriteString("тестовое сообщение от rsmon.ru")
		textBody.WriteString("тестовое сообщение от rsmon.ru")
		markdownBody.WriteString("#### тестовое сообщение от rsmon.ru")
		htmlBody.WriteString("<h4>тестовое сообщение от rsmon.ru</h4>")

		return subject, textBody, markdownBody, htmlBody
	}

	if message.Kind == stateExp {
		if len(message.Events) > 0 {
			panic("exp message with events")
		}
		if message.Check == nil {
			panic("exp message with no check")
		}
		return TextExpires(message.Check)
	}

	if message.Check != nil {
		panic("up/down message with check")
	}

	if len(message.Events) == 1 {
		event := message.Events[0]
		switch message.Kind {
		case stateDown:
			return TextDownOne(&event)
		case stateUp:
			return TextUpOne(&event)
		default:
			panic("bad message kind " + message.Kind)
		}
	}
	switch message.Kind {
	case stateDown:
		subject.WriteString(GetDownMany(len(message.Events)))
	case stateUp:
		subject.WriteString(GetUpMany(len(message.Events)))
	default:
		panic("bad message kind" + message.Kind)
	}
	names := []string{}
	for _, evt := range message.Events { //nolint:gocritic // range copy is acceptable here
		names = append(names, evt.Monitor.GetLabel())
	}
	subject.WriteString(": ")
	subject.WriteString(strings.Join(names, ", "))

	asciiTable, markdownTable := RenderEventsTable(message, tn)

	textBody.WriteString(subject.String() + "\n")
	textBody.WriteString(asciiTable)

	markdownBody.WriteString("###### " + subject.String() + "\n\n")
	markdownBody.WriteString(markdownTable)

	htmlTable := blackfriday.Run([]byte(markdownTable))
	htmlBody.WriteString("<h4>Изменения статусов по мониторам:</h4>")
	htmlBody.Write(htmlTable)

	return subject, textBody, markdownBody, htmlBody
}