package console

import (
	"fmt"
	"strings"
)

// The nearest-region feature's API and operator messages (spec §19), as
// approved in the nearest-region copy record. Change none of them without a
// new copy review.
//
// Where a message takes a list ("Choose from: %s."), the caller passes the
// region codes and the message joins them with ", ". An empty list never
// renders as a list: the b variant drops the list sentence (codex plan-R4 2,
// a list names only what the door would accept, so it can be empty).

// reasonText turns a refusal reason (absent, not-hosting, no-secrets-key,
// not-eligible) into the words C16 puts in its brackets (R-absent,
// R-not-hosting, R-no-secrets-key, R-not-eligible). An unknown reason passes
// through unchanged.
func reasonText(reason string) string {
	switch reason {
	case "absent":
		return "no box runs there now"
	case "not-hosting":
		return "boxes there can't start instances"
	case "no-secrets-key":
		return "boxes there can't open this deployment's secrets"
	case "not-eligible":
		return "boxes there don't take ordinary instances"
	}
	return reason
}

// msgAppRegionUnavailable is C16, or C16b when can is empty. The verbs are
// the app's region code, the reason text and the joined list.
func msgAppRegionUnavailable(code, reason string, can []string) string {
	if len(can) == 0 {
		return fmt.Sprintf("this app's region %s can't take new instances right now (%s), and no other region this app may use can either. Try again later.",
			code, reasonText(reason))
	}
	return fmt.Sprintf("this app's region %s can't take new instances right now (%s). Pass a region to place this instance elsewhere. Regions that can: %s.",
		code, reasonText(reason), strings.Join(can, ", "))
}

// msgAppRegionNotAllowed is C17, or C17b when allowed is empty.
func msgAppRegionNotAllowed(code string, allowed []string) string {
	if len(allowed) == 0 {
		return fmt.Sprintf("this app's region %s is not one its instances may use, and no region they may use can take new instances right now. Try again later.", code)
	}
	return fmt.Sprintf("this app's region %s is not one its instances may use. Allowed: %s. Pass a region to choose one.",
		code, strings.Join(allowed, ", "))
}

// msgRegionUnknown is C18, or C18b when choices is empty.
func msgRegionUnknown(code string, choices []string) string {
	if len(choices) == 0 {
		return fmt.Sprintf("region %s is not one this platform runs in. Run the command without --region.", code)
	}
	return fmt.Sprintf("region %s is not one this platform runs in. Choose from: %s.", code, strings.Join(choices, ", "))
}

// msgRegionNotArmed is C19, or C19b when choices is empty.
func msgRegionNotArmed(code string, choices []string) string {
	if len(choices) == 0 {
		return fmt.Sprintf("region %s can't take new apps right now. Run the command without --region.", code)
	}
	return fmt.Sprintf("region %s can't take new apps right now. Choose from: %s.", code, strings.Join(choices, ", "))
}

// msgAppRegionUnreadable is C20.
const msgAppRegionUnreadable = "could not read this app's region. Try again."

// msgReplicaOverlap is C26. The region code fills both verbs.
func msgReplicaOverlap(code string) string {
	return fmt.Sprintf("this app's region %s is also one of this instance's replica placements. Pass a region for the instance, or drop %s from replicas.", code, code)
}

// msgPolicyUnreadable is C27.
const msgPolicyUnreadable = "could not read this app's instance policy, so there is no region suggestion. Try again."

// msgAppRegionUnconfirmed is C28.
func msgAppRegionUnconfirmed(code string) string {
	return fmt.Sprintf("could not confirm that this app's region %s can take new instances. Try again, or pass a region.", code)
}

// msgPlacementDiscrepancy is C29, an operator log line. The app name fills
// the second and third verbs.
func msgPlacementDiscrepancy(host, app, code string) string {
	return fmt.Sprintf("possible placement discrepancy: %s of %s has no region, but %s's region is %s. It may be a deliberate home override; review it.", host, app, app, code)
}

// msgNoSecretsKey is C31 (R9).
func msgNoSecretsKey(code string) string {
	return fmt.Sprintf("region %s can't run instances right now: its boxes don't hold this deployment's secrets key, so an instance there would start without its config or secrets. Choose another region.", code)
}