import { Pencil, Plus, Trash2 } from 'lucide-react'
import { useState } from 'react'
import { api } from '@shared/api/client'
import type { AgentDto, KindDto, Page, ParamDto, TargetDto, TaskDto } from '@shared/api/types'
import { TARGET_STATUS, rejectText } from '@shared/targets'
import { fmtTime } from '@shared/format'
import { useQuery } from '@shared/hooks'
import { Chip, Confirm, Dialog, Empty, ErrorNotice, Field, Segmented, Spinner, useAction } from '@shared/ui'

/** 任务分两类：Agent 之间（线路任务，两个 Agent 之间测）和单个 Agent（Agent 自己去测一个外部地址）。 */
type Category = 'between' | 'single'
type Mode = 'template' | 'override' | 'own'

/** 模板（对所有 Agent）、覆盖（改某个模板）、专属（只属于一个 Agent 的单个 Agent 任务）。 */
const modeOf = (t: TaskDto): Mode => (!t.agent_id ? 'template' : t.base_task_id ? 'override' : 'own')
const categoryOf = (t: TaskDto): Category => (t.scope === 'target' ? 'single' : 'between')

/** 采集方法的中文名、协议和一句话说明；Backend 目录里是英文，这里按 id 补充，没有登记的回退到目录里的标题。 */
const KIND_INFO: Record<string, { name: string; proto: string; desc: string }> = {
  quic_ping: { name: 'QUIC 往返', proto: 'QUIC', desc: '两个 Agent 之间用 QUIC Datagram 持续往返，测 RTT、丢包、乱序；频率按丢包情况自适应。' },
  tcp_ping: { name: 'TCP 往返', proto: 'TCP', desc: '两个 Agent 之间用 TCP 小消息持续往返，测 RTT、重传，并采集内核 tcp_info。' },
  quic_stream: { name: 'QUIC 持续流量', proto: 'QUIC', desc: '按固定码率或阶梯发 QUIC Datagram，测高负载下的丢包和抖动。只用于按需测试。' },
  tcp_transfer: { name: 'TCP 多流传输', proto: 'TCP', desc: '多条 TCP 连接并行灌包，测吞吐和重传。只用于按需测试。' },
  tcp_connect: { name: 'TCP 建连', proto: 'TCP', desc: '只建立连接，不发 HTTP 请求：反复完成 TCP 三次握手（可选再做 TLS 握手），记录各阶段耗时和成功率。要测网页响应请用「HTTP 请求」。' },
  tls_hold: { name: 'TLS 长连接保持', proto: 'TLS', desc: '保持一条 TLS 长连接并定期心跳，记录重置次数和存活时间。' },
  icmp_ping: { name: 'ICMP 往返', proto: 'ICMP', desc: 'Agent 对目标地址发 ICMP echo，测 RTT 和丢包。' },
  http_request: { name: 'HTTP 请求', proto: 'HTTP', desc: 'Agent 请求一个 URL（HTTP/1.1、HTTP/2 或 HTTP/3），记录 DNS、建连、首字节、总耗时和状态码；频率按失败率自适应。' },
}

const kindName = (id: string, fallback?: string) => KIND_INFO[id]?.name ?? fallback ?? id

/** 采集方法：中文名、协议标签和 id；用在任务列表和选择框里。 */
function KindCell({ id }: { id: string }) {
  const info = KIND_INFO[id]
  return (
    <div className="task-kind">
      <b>{kindName(id)}</b>
      <span className="faint task-kind-id">
        {info ? `${info.proto} · ` : ''}
        <span className="mono">{id}</span>
      </span>
    </div>
  )
}

/** 参数摘要：每个参数一个小标签，换行显示。 */
function ParamChips({ params }: { params: Record<string, unknown> }) {
  const entries = Object.entries(params)
  if (entries.length === 0) return <span className="faint">默认参数</span>
  return (
    <span className="task-params">
      {entries.map(([k, v]) => (
        <span key={k} className="mono">
          {k}=<b>{String(v)}</b>
        </span>
      ))}
    </span>
  )
}

/** 按 Kind 声明的参数规格生成表单：只提交和默认值不同的那些。 */
function ParamForm({ params, values, onChange }: { params: ParamDto[]; values: Record<string, unknown>; onChange: (v: Record<string, unknown>) => void }) {
  const set = (name: string, value: unknown, fallback: unknown) => {
    const next = { ...values }
    if (value === '' || value === undefined || value === fallback) delete next[name]
    else next[name] = value
    onChange(next)
  }
  const field = (p: ParamDto) => {
        const current = values[p.name]
        const hint = [p.description, p.min !== null && p.min !== undefined ? `最小 ${p.min}` : '', p.max !== null && p.max !== undefined ? `最大 ${p.max}` : '', p.unit ?? ''].filter(Boolean).join(' · ')
        return (
          <Field key={p.name} label={`${p.name}（默认 ${JSON.stringify(p.default)}）`} hint={hint}>
            {p.type === 'bool' ? (
              <select className="select" value={current === undefined ? '' : String(current)} onChange={(e) => set(p.name, e.target.value === '' ? undefined : e.target.value === 'true', p.default)}>
                <option value="">默认</option>
                <option value="true">是</option>
                <option value="false">否</option>
              </select>
            ) : p.values && p.values.length > 0 ? (
              <select className="select" value={current === undefined ? '' : String(current)} onChange={(e) => set(p.name, e.target.value, p.default)}>
                <option value="">默认</option>
                {p.values.map((v) => (
                  <option key={String(v)} value={String(v)}>
                    {String(v)}
                  </option>
                ))}
              </select>
            ) : (
              <input
                className="input"
                type={p.type === 'string' ? 'text' : 'number'}
                step={p.type === 'int' ? 1 : 'any'}
                value={current === undefined ? '' : String(current)}
                placeholder={String(p.default)}
                onChange={(e) => set(p.name, p.type === 'string' ? e.target.value : e.target.value === '' ? '' : Number(e.target.value), p.default)}
              />
            )}
          </Field>
        )
  }
  // 前几个是最常调的，其余折叠起来（自适应、超时这类参数很多时表单太长）
  const main = params.slice(0, 4)
  const more = params.slice(4)
  return (
    <>
      <div className="form-grid">{main.map(field)}</div>
      {more.length > 0 ? (
        <details className="param-more">
          <summary>更多参数（{more.length}）</summary>
          <div className="form-grid">{more.map(field)}</div>
        </details>
      ) : null}
    </>
  )
}

function TaskDialog({ task, category, kinds, agents, templates, onClose, onSaved }: { task?: TaskDto; category: Category; kinds: KindDto[]; agents: AgentDto[]; templates: TaskDto[]; onClose: () => void; onSaved: () => void }) {
  const { busy, run } = useAction()
  const editing = Boolean(task)
  const [kindId, setKindId] = useState(task?.kind ?? '')
  const [everyone, setEveryone] = useState(task ? !task.agent_id : true)
  const [picked, setPicked] = useState<string[]>(task?.agent_id ? [task.agent_id] : [])
  const [target, setTarget] = useState(task?.target ?? '')
  const [values, setValues] = useState<Record<string, unknown>>(task ? { ...(task.params as Record<string, unknown>) } : {})
  const [enabled, setEnabled] = useState(task?.enabled ?? true)

  const single = category === 'single'
  const kind = kinds.find((k) => k.id === kindId)
  // 「Agent 之间」的任务只有模板；只改某几个 Agent 时是覆盖这个方法的模板，所以要先有模板
  const template = templates.find((t) => categoryOf(t) === category && t.kind === kindId)
  const blocked = !editing && !everyone && !single && !template
  const needsTarget = single && (everyone || !template)

  const kindChoices = kinds.filter((k) => k.scopes.includes(single ? 'target' : 'line'))
  const toggle = (id: string) => setPicked((current) => (current.includes(id) ? current.filter((x) => x !== id) : [...current, id]))

  const submit = async () => {
    const ok = await run(async () => {
      if (task) {
        await api.patch(`/api/admin/tasks/${task.id}`, { params: values, enabled, target: single && target ? target : undefined })
        return
      }
      const base = { scope: single ? 'target' : 'line', kind: kindId, params: values, enabled }
      if (everyone) {
        await api.post('/api/admin/tasks', { ...base, target: single ? target : null, agent_id: null, base_task_id: null })
        return
      }
      for (const agentId of picked) {
        await api.post('/api/admin/tasks', { ...base, target: single && target ? target : null, agent_id: agentId, base_task_id: !single || template ? (template?.id ?? null) : null })
      }
    }, '已保存')
    if (ok) {
      onSaved()
      onClose()
    }
  }

  const scopeLine = editing
    ? task?.agent_id
      ? `作用于 ${agents.find((a) => a.id === task.agent_id)?.name ?? task.agent_id}`
      : '作用于所有 Agent，包括以后新加入的'
    : everyone
      ? '保存后立即对所有 Agent 生效，以后新加入的 Agent 也会自动执行'
      : single
        ? '只对选中的 Agent 生效'
        : '只调整选中 Agent 的参数（覆盖该方法的模板），其他 Agent 不变'

  return (
    <Dialog
      title={editing ? '修改任务' : single ? '添加单个 Agent 任务' : '添加 Agent 之间的任务'}
      onClose={onClose}
      actions={
        <>
          <button type="button" className="btn text" onClick={onClose}>
            取消
          </button>
          <button type="button" className="btn primary" disabled={busy || !kind || blocked || (needsTarget && !target) || (!editing && !everyone && picked.length === 0)} onClick={submit}>
            保存
          </button>
        </>
      }
    >
      <div className="stack">
        {editing ? (
          <div className="task-kind">
            <KindCell id={task!.kind} />
          </div>
        ) : (
          <Field label="采集方法">
            <select className="select" value={kindId} onChange={(e) => { setKindId(e.target.value); setValues({}); setTarget('') }}>
              <option value="">选择要做什么测量</option>
              {kindChoices.map((k) => (
                <option key={k.id} value={k.id}>
                  {kindName(k.id, k.title)}（{k.id}）
                </option>
              ))}
            </select>
          </Field>
        )}
        {single ? (
          <Field label="目标" hint={kindId === 'http_request' ? 'http:// 或 https:// 开头的 URL，例如 https://example.com/health' : 'IP 或域名，可带端口，例如 1.1.1.1、example.com:443'}>
            <input className="input" value={target} placeholder={!everyone && template ? (template.target ?? '') : ''} onChange={(e) => setTarget(e.target.value)} />
          </Field>
        ) : null}
        {!editing && kind ? (
          <Field label="应用到" hint={scopeLine}>
            <Segmented
              options={[
                { value: 'all' as const, label: '所有 Agent' },
                { value: 'some' as const, label: '指定 Agent' },
              ]}
              value={everyone ? 'all' : 'some'}
              onChange={(v) => setEveryone(v === 'all')}
            />
          </Field>
        ) : editing ? (
          <p className="muted">{scopeLine}</p>
        ) : null}
        {!editing && kind && !everyone ? (
          <div className="task-agents">
            {agents.map((a) => (
              <label key={a.id} className="switch">
                <input type="checkbox" checked={picked.includes(a.id)} onChange={() => toggle(a.id)} />
                {a.name}
              </label>
            ))}
          </div>
        ) : null}
        {blocked ? <p className="warn-text">「{kindName(kindId)}」还没有对所有 Agent 的模板：先添加一个应用到「所有 Agent」的任务，再对某几个 Agent 单独调整。</p> : null}
        {kind ? (
          <>
            <p className="muted">{KIND_INFO[kind.id]?.desc ?? kind.description}</p>
            <ParamForm params={kind.params} values={values} onChange={setValues} />
          </>
        ) : null}
        <label className="switch">
          <input type="checkbox" checked={enabled} onChange={(e) => setEnabled(e.target.checked)} />
          启用
        </label>
      </div>
    </Dialog>
  )
}

/** 单个 Agent 任务的运行情况：每个执行它的 Agent 一个状态标签；悬停看说明和原因。 */
function RunCell({ items }: { items: TargetDto[] }) {
  if (items.length === 0) return <span className="faint">没有 Agent 在执行</span>
  return (
    <span className="task-run">
      {items.map((t) => (
        <span key={t.agent_id} title={`${TARGET_STATUS[t.status].hint}${t.status === 'rejected' ? `\n${rejectText(t.reason)}` : ''}${t.last_sample ? `\n最后一次数据 ${fmtTime(t.last_sample)}` : ''}`}>
          <Chip tone={TARGET_STATUS[t.status].tone}>
            {t.agent_name} · {TARGET_STATUS[t.status].label}
          </Chip>
        </span>
      ))}
    </span>
  )
}

/** 一个模板带着它的覆盖排在一起（覆盖缩进），其余的专属任务跟在后面；这样同一个方法不会在列表里到处出现。 */
function groupRows(tasks: TaskDto[]): { task: TaskDto; child: boolean }[] {
  const byId = new Set(tasks.map((t) => t.id))
  const rows: { task: TaskDto; child: boolean }[] = []
  for (const template of tasks.filter((t) => !t.agent_id)) {
    rows.push({ task: template, child: false })
    for (const over of tasks.filter((t) => t.base_task_id === template.id)) rows.push({ task: over, child: true })
  }
  // 模板已经不在的覆盖和专属任务
  for (const t of tasks.filter((t) => t.agent_id && !(t.base_task_id && byId.has(t.base_task_id)))) rows.push({ task: t, child: false })
  return rows
}

/** 作用范围：模板（所有 Agent）、覆盖（某个 Agent 改某个模板）、专属（只属于一个 Agent）。 */
function ScopeCell({ task, agentName }: { task: TaskDto; agentName: (id: string | null) => string }) {
  const mode = modeOf(task)
  return (
    <span className="row" style={{ gap: 6 }}>
      {mode === 'template' ? <Chip tone="accent">模板</Chip> : mode === 'override' ? <Chip>覆盖</Chip> : <Chip>专属</Chip>}
      <span className={mode === 'template' ? 'muted' : undefined}>{agentName(task.agent_id)}</span>
    </span>
  )
}

interface TaskTableProps {
  title: string
  hint: string
  category: Category
  tasks: TaskDto[]
  loaded: boolean
  agentName: (id: string | null) => string
  onEdit: (t: TaskDto) => void
  onDelete: (t: TaskDto) => void
  onToggle: (t: TaskDto) => void
  onAdd: () => void
  canAdd: boolean
  targets: TargetDto[]
}

/** 一类任务一张表：Agent 之间的看「作用范围」，单个 Agent 的看「Agent」和「目标」。 */
function TaskTable({ title, hint, category, tasks, loaded, agentName, onEdit, onDelete, onToggle, onAdd, canAdd, targets }: TaskTableProps) {
  const single = category === 'single'
  return (
    <section className="card" style={{ padding: '8px 12px' }}>
      <div className="row" style={{ alignItems: 'baseline', gap: 8, padding: '4px 0 8px' }}>
        <b>{title}</b>
        <span className="muted">{hint}</span>
        <button type="button" className="btn small right" onClick={onAdd} disabled={!canAdd}>
          <Plus size={14} />
          添加任务
        </button>
      </div>
      {tasks.length === 0 ? (
        <Empty>{loaded ? '没有任务' : '加载中…'}</Empty>
      ) : (
        <table className="table">
          <thead>
            <tr>
              <th>采集方法</th>
              <th>作用范围</th>
              {single ? <th>目标</th> : null}
              <th>参数</th>
              {single ? <th>运行情况</th> : null}
              <th>状态</th>
              <th>更新</th>
              <th />
            </tr>
          </thead>
          <tbody>
            {groupRows(tasks).map(({ task: t, child }) => (
              <tr key={t.id} className={child ? 'task-child' : undefined}>
                <td>{child ? <span className="task-branch">↳</span> : <KindCell id={t.kind} />}</td>
                <td>
                  <ScopeCell task={t} agentName={agentName} />
                </td>
                {single ? <td className="mono">{t.target ?? <span className="faint">沿用模板</span>}</td> : null}
                <td>
                  <ParamChips params={t.params as Record<string, unknown>} />
                </td>
                {single ? (
                  <td>
                    <RunCell items={targets.filter((x) => x.task_id === t.id)} />
                  </td>
                ) : null}
                <td>
                  <button type="button" className="btn small" onClick={() => onToggle(t)}>
                    {t.enabled ? <Chip tone="ok">已启用</Chip> : <Chip>已停用</Chip>}
                  </button>
                </td>
                <td className="muted">{fmtTime(t.updated_at)}</td>
                <td className="r">
                  <span className="row" style={{ justifyContent: 'flex-end' }}>
                    <button type="button" className="btn small" onClick={() => onEdit(t)}>
                      <Pencil size={14} />
                    </button>
                    <button type="button" className="btn small danger" onClick={() => onDelete(t)}>
                      <Trash2 size={14} />
                    </button>
                  </span>
                </td>
              </tr>
            ))}
          </tbody>
        </table>
      )}
    </section>
  )
}

export function Tasks() {
  const tasks = useQuery(() => api.get<Page<TaskDto>>('/api/admin/tasks'), [])
  const kinds = useQuery(() => api.get<Page<KindDto>>('/api/public/catalog/kinds'), [])
  const agents = useQuery(() => api.get<Page<AgentDto>>('/api/admin/agents'), [])
  // 单个 Agent 任务有没有跑起来：每个 Agent 一个状态，10 秒刷新一次
  const targets = useQuery(() => api.get<Page<TargetDto>>('/api/public/targets', { range: '1h' }), [], 10_000)
  // 新建时记下是哪一类（从哪张表点的添加），修改时是任务本身
  const [editing, setEditing] = useState<TaskDto | Category>()
  const [deleting, setDeleting] = useState<TaskDto>()
  const { run } = useAction()

  const all = tasks.data?.items ?? []
  const between = all.filter((t) => categoryOf(t) === 'between')
  const single = all.filter((t) => categoryOf(t) === 'single')
  const toggle = async (t: TaskDto) => {
    await run(() => api.patch(`/api/admin/tasks/${t.id}`, { enabled: !t.enabled }))
    tasks.reload()
  }
  const agentName = (id: string | null) => (id ? (agents.data?.items.find((a) => a.id === id)?.name ?? id) : '全部 Agent')

  return (
    <>
      <header>
        <h1>任务</h1>
        <span className="right row">
          {tasks.loading && !tasks.data ? <Spinner /> : null}
        </span>
      </header>
      <ErrorNotice error={tasks.error ?? kinds.error} />
      <div className="stack">
        <TaskTable
          title="Agent 之间"
          hint="两个 Agent 之间的线路测量：模板对所有线路生效，覆盖只改某个 Agent 的参数"
          category="between"
          tasks={between}
          loaded={Boolean(tasks.data)}
          agentName={agentName}
          onEdit={setEditing}
          onDelete={setDeleting}
          onToggle={toggle}
          onAdd={() => setEditing('between')}
          canAdd={Boolean(kinds.data && agents.data)}
          targets={[]}
        />
        <TaskTable
          title="单个 Agent"
          hint="Agent 自己去测一个外部地址：模板对所有 Agent 生效，也可以只给某个 Agent 专属或覆盖"
          category="single"
          tasks={single}
          loaded={Boolean(tasks.data)}
          agentName={agentName}
          onEdit={setEditing}
          onDelete={setDeleting}
          onToggle={toggle}
          onAdd={() => setEditing('single')}
          canAdd={Boolean(kinds.data && agents.data)}
          targets={targets.data?.items ?? []}
        />
      </div>
      {editing && kinds.data && agents.data ? (
        <TaskDialog
          task={typeof editing === 'string' ? undefined : editing}
          category={typeof editing === 'string' ? editing : categoryOf(editing)}
          kinds={kinds.data.items}
          agents={agents.data.items}
          templates={all.filter((t) => modeOf(t) === 'template')}
          onClose={() => setEditing(undefined)}
          onSaved={() => { tasks.reload(); targets.reload() }}
        />
      ) : null}
      {deleting ? (
        <Confirm
          title="删除任务"
          danger
          confirmText="删除"
          onClose={() => setDeleting(undefined)}
          onConfirm={async () => {
            await run(() => api.del(`/api/admin/tasks/${deleting.id}`), '已删除')
            tasks.reload()
          }}
        >
          删除之后，Agent 会在下一次同步时停止这个任务。
        </Confirm>
      ) : null}
    </>
  )
}