/** Shared user-facing diagnostics for execution failures and recorded-workflow recovery. */

import type { WorkflowSource } from "../engine/types.ts"
import { workflowSourceLabel } from "./workflow-source.ts"

export interface WorkflowCrashIdentity {
	readonly workflowName: string
	readonly runId: string
	readonly path?: string
}

export interface WorkflowCrashDetails extends WorkflowCrashIdentity {
	readonly cause: string
}

export function workflowCrashHeading(details: WorkflowCrashIdentity): string {
	return `workflow "${details.workflowName}" crashed${details.path ? ` at "${details.path}"` : ""} (run ${details.runId})`
}

export function workflowCrashRecovery(runId: string): readonly [string, string] {
	return [`Resume: /workflow resume ${runId}`, `Details: /workflow status ${runId}`]
}

export function workflowCrashMessage(details: WorkflowCrashDetails): string {
	return [
		workflowCrashHeading(details),
		`  ${details.cause}`,
		...workflowCrashRecovery(details.runId).map((line) => `  ${line}`),
	].join("\n")
}

export function workflowFailureLine(details: Pick<WorkflowCrashDetails, "path" | "cause">): string {
	return `Failure${details.path ? ` at "${details.path}"` : ""}: ${details.cause}`
}

export function recordedWorkflowLoadFailure(options: {
	readonly workflowName: string
	readonly runId: string
	readonly workflowSource: WorkflowSource
	readonly action: "resume" | "show status"
	readonly cause?: string
}): string {
	const sourceKind = options.workflowSource.kind === "file" ? "File" : "Built-in"
	return [
		`workflow "${options.workflowName}" cannot ${options.action} (run ${options.runId})`,
		`  ${sourceKind}: ${workflowSourceLabel(options.workflowSource)}`,
		`  ${options.cause ?? defaultLoadFailure(options.workflowSource)}`,
		"  The recorded run has been preserved.",
	].join("\n")
}

function defaultLoadFailure(source: WorkflowSource): string {
	return source.kind === "file" ? "The workflow file no longer exists." : "The package-owned workflow is unavailable."
}

export function missingWorkflowProvenance(runId: string, action: "resumed" | "shown"): string {
	return [
		`workflow run ${runId} cannot be ${action}`,
		"  Its history does not record the workflow source it came from.",
		"  The recorded run has been preserved.",
	].join("\n")
}