package backendupdate

import (
	"encoding/json"

	"yms-daemon/internal/hostnginx"
	"yms-daemon/internal/transaction"
)

func gatewaySwitchIntent(request persistedRequest, before hostnginx.Snapshot, after hostnginx.Snapshot) transaction.StepIntent {
	return stepIntent("backend.gateway.switch", "switch host Nginx backend upstream", struct {
		BeforePort int    `json:"beforePort"`
		BeforeHash string `json:"beforeHash"`
		AfterPort  int    `json:"afterPort"`
		AfterHash  string `json:"afterHash"`
	}{before.ActivePort, snapshotDigest(before), after.ActivePort, snapshotDigest(after)})
}

func activeLinkIntent(request persistedRequest, installedPath string) transaction.StepIntent {
	return stepIntent("backend.native.active-link", "replace backend compatibility link", struct {
		Path          string    `json:"path"`
		Before        pathState `json:"before"`
		InstalledPath string    `json:"installedPath"`
	}{request.ActiveJARPath, request.ActiveJARBefore, installedPath})
}

func stopPreviousUnitIntent(request persistedRequest) transaction.StepIntent {
	return stepIntent("backend.previous-unit.stop", "stop previous backend unit after drain", struct {
		Unit string `json:"unit"`
	}{request.PreviousUnit})
}

func activeLinkRestoreIntent(request persistedRequest) transaction.StepIntent {
	return stepIntent("backend.native.active-link.restore", "restore backend compatibility path", struct {
		Path   string    `json:"path"`
		Before pathState `json:"before"`
	}{request.ActiveJARPath, request.ActiveJARBefore})
}

func gatewayRestoreIntent(request persistedRequest) transaction.StepIntent {
	return stepIntent("backend.gateway.restore", "restore host Nginx backend upstream", struct {
		Port int `json:"port"`
	}{request.PreviousGatewayPort})
}

func stopTargetUnitIntent(request persistedRequest) transaction.StepIntent {
	return stepIntent("backend.target-unit.stop", "stop compensated backend target unit", struct {
		Unit string `json:"unit"`
	}{request.TargetUnit})
}

func restoreTargetSlotIntent(request persistedRequest, installedPath string) transaction.StepIntent {
	return stepIntent("backend.target-slot.restore", "restore compensated backend target slot", struct {
		Path           string `json:"path"`
		InstalledPath  string `json:"installedPath"`
		PreviousTarget string `json:"previousTarget"`
	}{request.TargetSlotJAR, installedPath, request.PreviousSlotTarget})
}

func stepIntent(key string, name string, value any) transaction.StepIntent {
	content, err := json.Marshal(value)
	if err != nil {
		panic(err)
	}
	return transaction.StepIntent{Key: key, Name: name, Intent: content}
}