// 工具调用按类别合并成时间线的一行。新增类别必须补进 ToolKind 与两处 switch，
// 否则 never 检查会在编译期失败。
import type { Part } from './contracts'

export type ToolKind = 'read' | 'search' | 'exec' | 'write' | 'card' | 'delegate' | 'plan' | 'other'

const READ = new Set(['fs_read_file', 'fs_list_dir', 'read_conversation', 'list_conversations'])
const SEARCH = new Set(['knowledge_search', 'tavily_search', 'web_search', 'history_search'])
const EXEC = new Set(['run_shell', 'run_python'])
const WRITE = new Set(['write_artifact', 'register_artifact', 'fs_write_file'])
const CARD = new Set(['submit_card', 'card_begin', 'card_append', 'card_commit'])
const DELEGATE = new Set(['delegate_task', 'squad_orchestrate'])
const PLAN = new Set(['update_plan', 'update_todos'])

export function toolKind(name: string): ToolKind {
  if (READ.has(name)) return 'read'
  if (SEARCH.has(name)) return 'search'
  if (EXEC.has(name)) return 'exec'
  if (WRITE.has(name)) return 'write'
  if (CARD.has(name)) return 'card'
  if (DELEGATE.has(name)) return 'delegate'
  if (PLAN.has(name)) return 'plan'
  return 'other'
}

function argOf(raw: string | undefined, keys: string[]): string {
  if (!raw) return ''
  try {
    const v = JSON.parse(raw) as Record<string, unknown>
    for (const k of keys) {
      const x = v[k]
      if (typeof x === 'string' && x.trim()) return x.trim()
    }
  } catch {
    return ''
  }
  return ''
}

function firstLine(s: string): string {
  const line = s.split('\n').map(x => x.trim()).find(Boolean) ?? ''
  return line.length > 80 ? `${line.slice(0, 80)}…` : line
}

/** 从工具参数里取出给用户看的一行：路径、查询词或脚本首行。 */
export function toolHeadline(name: string, args?: string): string {
  const kind = toolKind(name)
  switch (kind) {
    case 'read': return argOf(args, ['path', 'file', 'conversationId']) || name
    case 'search': return argOf(args, ['query', 'q']) || name
    case 'exec': return firstLine(argOf(args, ['script', 'command', 'cmd'])) || name
    case 'write': return argOf(args, ['path', 'name', 'filename']) || name
    case 'card': return argOf(args, ['title']) || name
    case 'delegate': return argOf(args, ['task', 'goal', 'name']) || name
    case 'plan': return argOf(args, ['title']) || name
    case 'other': return name
    default: {
      const exhaustive: never = kind
      return exhaustive
    }
  }
}

export function toolGroupLabel(kind: ToolKind, count: number, running: boolean): string {
  switch (kind) {
    case 'read': return `查阅 · ${count} 个文件`
    case 'search': return `搜索 · ${count} 次`
    case 'exec': return running ? `运行命令 · ${count} 条` : `已运行命令 · ${count} 条`
    case 'write': return `写入文件 · ${count} 个`
    case 'card': return `卡片 · ${count} 张`
    case 'delegate': return `委派 · ${count} 个任务`
    case 'plan': return `更新计划 · ${count} 次`
    case 'other': return `工具 · ${count} 次`
    default: {
      const exhaustive: never = kind
      return exhaustive
    }
  }
}

export interface ToolGroupItem {
  name: string
  headline: string
  status?: 'ok' | 'error'
  summary?: string
  running: boolean
}

export type TimelineEntry =
  | { kind: 'thinking'; text: string; durationMs?: number; active: boolean }
  | { kind: 'text'; text: string }
  | { kind: 'tools'; toolKind: ToolKind; items: ToolGroupItem[] }
  | { kind: 'other'; part: Part }

/** 把时间线部件收成行：相邻同类工具合并，思考是否仍在进行由 live 与后续部件决定。 */
export function timelineEntries(parts: Part[], live: boolean): TimelineEntry[] {
  const out: TimelineEntry[] = []
  let i = 0
  while (i < parts.length) {
    const p = parts[i]
    if (p.type === 'tool_call') {
      const kind = toolKind(p.toolCall?.name ?? '')
      const items: ToolGroupItem[] = []
      while (i < parts.length && parts[i].type === 'tool_call' && toolKind(parts[i].toolCall?.name ?? '') === kind) {
        const call = parts[i]
        i++
        let res: Part | undefined
        if (parts[i]?.type === 'tool_result') {
          res = parts[i]
          i++
        }
        const status = res?.toolResult?.status
        items.push({
          name: call.toolCall?.name ?? '工具',
          headline: toolHeadline(call.toolCall?.name ?? '', call.toolCall?.arguments),
          status: status === 'ok' || status === 'error' ? status : undefined,
          summary: res?.toolResult?.summary,
          running: live && !res,
        })
      }
      out.push({ kind: 'tools', toolKind: kind, items })
      continue
    }
    if (p.type === 'tool_result') { i++; continue }
    if (p.type === 'thinking') {
      out.push({ kind: 'thinking', text: p.text ?? '', durationMs: p.durationMs, active: false })
      i++
      continue
    }
    if (p.type === 'text') {
      out.push({ kind: 'text', text: p.text ?? '' })
      i++
      continue
    }
    out.push({ kind: 'other', part: p })
    i++
  }
  if (live) {
    const idx = out.reduce((acc, e, n) => (e.kind === 'thinking' ? n : acc), -1)
    const entry = idx >= 0 ? out[idx] : undefined
    if (entry && entry.kind === 'thinking' && out.slice(idx + 1).every(e => e.kind === 'thinking')) {
      entry.active = true
    }
  }
  return out
}