// Package rolloutwords holds every member-facing phrase about a rollout:
// the causes of an attempt (zero-downtime spec §6.3), the reasons a build
// failed, the short states `carlos instances list` and the console show
// (§9.1, §9.2), and the events a box writes to the platform log stream
// (§9.4). One home, so the CLI, the console and the box never word one fact
// two ways. Every string here is approved copy, pinned by the zero-downtime
// copy record (docs/superpowers/plans/2026-10-07-zero-downtime-deploys-6-copy.json).
//
// A leaf: it imports nothing of this repo's, so the rollout manager and the
// activator can use it without an import cycle.
package rolloutwords

import "fmt"

// causes are the attempt causes of spec §6.3, as a member reads them.
var causes = map[string]string{
	"release": "new release",
	"install": "installed by hand",
	"retry":   "retry",
	"restart": "carlos restart",
	"config":  "config change",
}

// Cause renders an attempt's cause. One this binary does not know is shown
// as its own word, never dropped.
func Cause(c string) string {
	if p, ok := causes[c]; ok {
		return p
	}
	return c
}

// reasons are the box's failure words, read after "because".
var reasons = map[string]string{
	"health":  "it did not answer its health check within 30 seconds",
	"settle":  "it stopped within 10 seconds of answering its health check",
	"exit":    "it exited before it was ready",
	"staging": "the copy on the box did not match the release",
	"reused":  "this version name was shipped twice with different content, so ship it under a new name",
}

const reasonUnknown = "it failed (%s)"

// Reason renders a failure word. One this binary does not know still says
// the build failed, and carries the box's own word for it.
func Reason(r string) string {
	if p, ok := reasons[r]; ok {
		return p
	}
	return fmt.Sprintf(reasonUnknown, r)
}

// Event formats (spec §9.4), one per text function in internal/rollout/events.go
// plus the bounce. TestVerbsAreWhereTheCallersPutThem pins each verb count.
const (
	// Emitted for every attempt, overlap, hold and a socketless worker's
	// stop-then-start alike (rollout's execute and executeWorker), so it
	// says nothing about the mode (Astra plan 6 R1 #8).
	EventSwapping       = "starting build %s (%s)"
	EventSwapped        = "now serving build %s. The previous build finished its requests and stopped in %s"
	EventSwapFailed     = "build %s did not take over, because %s. Still serving build %s"
	EventHoldDown       = "build %s failed and nothing is serving. This app swaps in hold mode, so nothing falls back by itself. Roll back with carlos rollback"
	EventCohortHalted   = "rollout of build %s stopped on box %s, because %s. Instances on that box that have not served it stay on their last good build"
	EventFallbackServed = "build %s failed to start, so the last good build, %s, is serving instead"
	EventConfigPending  = "new config reached this box but is not in use yet, because %s. Trying again in %s"
	EventStagingRefused = "build %s is not staged correctly on this box, so the box asked for it to be staged again"
	EventBounceInstance = "instance restarting (%s)"
	EventBounceSidecar  = "sidecar restarting (%s)"
)

// States: the REASON column of `carlos instances list` (spec §9.1).
const (
	StateHeld          = "held: build %s failed on this box"
	StateRollingOut    = "rolling out"
	StateAsleep        = "starts %s on its next request"
	StateConfigPending = "config delivered, not active"
)

const unavailableDeclined = "its box cannot run two builds side by side, so it restarts instances the old way"

// unavailablePhrases are the member-facing reasons a box cannot run zero-downtime deploys,
// keyed by the codes in status.RolloutReport.Unavailable.
var unavailablePhrases = map[string]string{
	"no-cgroup-delegation":    unavailableDeclined,
	"no-generation-control":   unavailableDeclined,
	"generations-off":         unavailableDeclined,
	"host-claims-on":          unavailableDeclined,
	"cgroup-placement-failed": unavailableDeclined,
	"no-deploy-store":         "its box cannot start instances: the deploy store is unavailable",
	"no-release-key":          "its box cannot start instances: the release key is unavailable",
	"failure-book-unreadable": "its box cannot start instances: its record of failed builds cannot be read",
}

const unavailableUnknown = "its box reports a rollout problem (%s)"

// Unavailable is the member-facing phrase for a box's
// RolloutReport.Unavailable code. An unknown code (a newer box) reads
// through unavailableUnknown with the code itself.
func Unavailable(code string) string {
	if p, ok := unavailablePhrases[code]; ok {
		return p
	}
	return fmt.Sprintf(unavailableUnknown, code)
}

// UnavailableDeclines reports whether code is one under which the box
// declined CARLOS_SWAP=overlap and runs today's stop-then-start paths. An
// unknown code (a newer box) is not: a reader must not assume its instances
// are safe to wake.
func UnavailableDeclines(code string) bool {
	switch code {
	case "no-cgroup-delegation", "no-generation-control", "generations-off", "host-claims-on", "cgroup-placement-failed":
		return true
	default:
		return false
	}
}

// UnavailableRefuses reports whether code is one under which the box
// refuses every managed start (as opposed to running today's paths).
func UnavailableRefuses(code string) bool {
	switch code {
	case "no-deploy-store", "no-release-key", "failure-book-unreadable":
		return true
	default:
		return false
	}
}