/**
 * Pure status helpers for the session UI — NO React, NO realtime, NO xterm imports,
 * so they're trivially unit-testable and safe to pull anywhere.
 */
import type { TerminalStatus } from '../terminal/themes'
import type { SessionStatusKind, SessionSummary } from './types'

/** Visual tokens for a resolved session status. */
export interface SessionStatusVisual {
  kind: SessionStatusKind
  label: string
  /** Tailwind-token classes for the badge pill (light + dark friendly). */
  className: string
  /** Tailwind-token colour class for a status icon/text. */
  toneClassName: string
}

const DEFAULT_LABELS: Record<SessionStatusKind, string> = {
  active: 'Active',
  success: 'Success',
  error: 'Error',
  warning: 'Needs review',
  idle: 'Idle',
  completed: 'Completed',
}

const KIND_CLASSES: Record<SessionStatusKind, string> = {
  active: 'bg-primary/15 text-primary border border-primary/30',
  success: 'bg-emerald-500/15 text-emerald-600 dark:text-emerald-400 border border-emerald-500/30',
  error: 'bg-red-500/15 text-red-600 dark:text-red-400 border border-red-500/30',
  warning: 'bg-amber-500/15 text-amber-600 dark:text-amber-400 border border-amber-500/30',
  idle: 'bg-muted text-muted-foreground border border-border',
  completed: 'bg-muted text-muted-foreground border border-border',
}

const KIND_TONE: Record<SessionStatusKind, string> = {
  active: 'text-primary',
  success: 'text-emerald-600 dark:text-emerald-400',
  error: 'text-red-600 dark:text-red-400',
  warning: 'text-amber-600 dark:text-amber-400',
  idle: 'text-muted-foreground',
  completed: 'text-muted-foreground',
}

/**
 * Resolve the effective status of a session view-model. Prefers an explicit
 * `status`; otherwise derives `active`/`idle` from `isActive`.
 */
export function resolveSessionStatus(
  session: Pick<SessionSummary, 'status' | 'statusLabel' | 'isActive'>,
): SessionStatusVisual {
  const kind: SessionStatusKind = session.status ?? (session.isActive ? 'active' : 'idle')
  return {
    kind,
    label: session.statusLabel ?? DEFAULT_LABELS[kind],
    className: KIND_CLASSES[kind],
    toneClassName: KIND_TONE[kind],
  }
}

/**
 * The connection states an `AgentSocket` reports (mirrors `@startsimpli/realtime`'s
 * `AgentSocketStatus`). Redefined locally so this module stays realtime-free.
 */
export type AgentConnectionStatus = 'idle' | 'connecting' | 'open' | 'reconnecting' | 'closed'

/** Map an agent socket status onto the terminal chrome's `TerminalStatus`. */
export function mapSocketStatus(status: AgentConnectionStatus): TerminalStatus {
  switch (status) {
    case 'open':
      return 'connected'
    case 'connecting':
    case 'reconnecting':
      return 'connecting'
    case 'idle':
    case 'closed':
    default:
      return 'disconnected'
  }
}