/**
 * 实施 / 规划会话 resume 的落点决策。纯函数，不碰 vscode API，便于单测。
 *
 * 角色由调用方明确传入，不从「有没有 cwd」反推：worktree 被清理后
 * 工单里的 worktreePath 会清空，靠 cwd 推断会把实施会话误判成规划。
 */
export type ResumeKind = 'implement' | 'brainstorm'

export function resumeSessionRole(kind: ResumeKind): '实施' | '规划' {
  return kind === 'implement' ? '实施' : '规划'
}

export function resumeTerminalName(kind: ResumeKind, sessionId: string, issueNumber?: number): string {
  return issueNumber !== undefined
    ? `issue-${issueNumber}-${resumeSessionRole(kind)}`
    : `Claude · ${sessionId.slice(0, 8)}`
}

export interface ResumeCwdInput {
  kind: ResumeKind
  workspaceRoot: string
  /** 已解析成绝对路径的 worktree；工单没记就 undefined */
  worktreeAbs?: string
  worktreeExists: boolean
}

export interface ResumeCwdPlan {
  cwd: string
  /** 实施会话但 worktree 已不在磁盘上（含工单里没记 worktreePath 的情况） */
  worktreeMissing: boolean
}

export function planResumeCwd(input: ResumeCwdInput): ResumeCwdPlan {
  if (input.kind !== 'implement')
    return { cwd: input.workspaceRoot, worktreeMissing: false }
  if (input.worktreeAbs && input.worktreeExists)
    return { cwd: input.worktreeAbs, worktreeMissing: false }
  return { cwd: input.workspaceRoot, worktreeMissing: true }
}