/**
 * Tool-card view computation over the mux live path: three standard card types
 * arrive on the frame, a presenterless tool ships no view field, a call-only
 * presenter keeps raw result content out of the view payload, and a throwing
 * presenter soft-falls to no view (the event still ships). Result pairing
 * works both through the live open-call table and the backscan fallback after
 * turn/end cleared it.
 */

import { describe, expect, it } from 'vitest'
import { Context } from 'cordis'
import AgentRegistry from '@deepseek-ai/dsh-agent'
import type { Agent } from '@deepseek-ai/dsh-agent'
import SessionStore from '@deepseek-ai/dsh-session'
import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
import ToolRegistry, { defineContentToolFixture } from '@deepseek-ai/dsh-tools'
import type { ContentBlock } from '@deepseek-ai/dsh-llm'
import { CallId } from '@deepseek-ai/dsh-llm'
import type { Session, SessionId } from '@deepseek-ai/dsh-session'
import type { ToolDefinition } from '@deepseek-ai/dsh-tools'
import UserInteractionService from '@deepseek-ai/dsh-user-interaction'
import type { MuxFrame, RpcRequest } from '@deepseek-ai/dsh-host-apiproxy/api'
import { RpcId } from '@deepseek-ai/dsh-host-apiproxy/api/rpc'
import { createApiProxy } from '@deepseek-ai/dsh-host-apiproxy'

const reply = (text: string): Promise<ContentBlock[]> => Promise.resolve([{ type: 'text', text }])

function tool(name: string, presenters: Pick<ToolDefinition, 'presentCall' | 'presentResult'>): ToolDefinition {
  return defineContentToolFixture({
    name,
    description: `tool ${name}`,
    parameters: {},
    execute: () => reply(`ran:${name}`),
    ...presenters,
  })
}

async function harness(): Promise<{ ctx: Context }> {
  const ctx = new Context()
  await ctx.plugin(SessionStore)
  await ctx.plugin(SystemPrompt, { persona: '' })
  await ctx.plugin(ToolRegistry)
  await ctx.plugin(UserInteractionService)
  await ctx.plugin(AgentRegistry)
  ctx.tools.register(tool('gen', {
    presentCall: () => ({ card: 'generic', title: 'gen call' }),
    presentResult: (_args, result) => ({ card: 'generic', title: result.isError ? 'gen failed' : 'gen done' }),
  }))
  ctx.tools.register(tool('term', {
    presentCall: args => ({ card: 'terminal', title: (args as { cmd?: string }).cmd ?? '' }),
    presentResult: () => ({ card: 'terminal', output: 'done' }),
  }))
  ctx.tools.register(tool('diffy', {
    presentCall: () => ({ card: 'diff', title: 'Write f.txt', diffs: [{ path: 'f.txt', oldText: null, newText: 'x' }] }),
  }))
  ctx.tools.register(tool('call-only', {
    presentCall: () => ({ card: 'generic', title: 'program', kind: 'execute', rawInput: 'return value' }),
  }))
  ctx.tools.register(tool('plain', {}))
  ctx.tools.register(tool('boom', {
    presentCall: () => { throw new Error('presenter exploded') },
  }))
  return { ctx }
}

/** Drain frames from an open mux stream until `count` session/event frames arrived. */
async function collect(iterable: AsyncIterable<RpcRequest<MuxFrame>>, count: number, abort: AbortController): Promise<MuxFrame[]> {
  const frames: MuxFrame[] = []
  for await (const frame of iterable) {
    frames.push(frame.payload)
    if (frames.filter(f => f.type === 'session/event').length >= count) abort.abort()
  }
  return frames
}

describe('mux live view computation', () => {
  it('attaches the three standard card views, omits view without a presenter, soft-falls on throw', async () => {
    const { ctx } = await harness()
    const api = createApiProxy(ctx, { provider: 'p', model: 'm', cwd: '/tmp', workspaceRoot: '/tmp' })
    const abort = new AbortController()
    const stream = api.events.mux({ rpcId: RpcId('t-mux'), payload: {} }, abort.signal)
    const collected = collect(stream, 9, abort)
    const rawResult = `RAW_RESULT:${'x'.repeat(64 * 1024)}`

    const session = ctx.sessions.create()
    session.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
    session.append('tool/call', { turn: 1, step: 1, callId: CallId('c-gen'), name: 'gen', arguments: '{}' })
    session.append('tool/call', { turn: 1, step: 1, callId: CallId('c-term'), name: 'term', arguments: '{"cmd":"echo hi"}' })
    session.append('tool/call', { turn: 1, step: 1, callId: CallId('c-diff'), name: 'diffy', arguments: '{}' })
    session.append('tool/call', { turn: 1, step: 1, callId: CallId('c-call-only'), name: 'call-only', arguments: '{}' })
    session.append('tool/result', { turn: 1, step: 1, callId: CallId('c-call-only'), content: [{ type: 'text', text: rawResult }], isError: false }, { surfaceOp: 'append' })
    session.append('tool/call', { turn: 1, step: 1, callId: CallId('c-plain'), name: 'plain', arguments: '{}' })
    session.append('tool/call', { turn: 1, step: 1, callId: CallId('c-boom'), name: 'boom', arguments: '{}' })
    session.append('tool/result', { turn: 1, step: 1, callId: CallId('c-gen'), content: [{ type: 'text', text: 'ok' }], isError: false }, { surfaceOp: 'append' })

    const frames = await collected
    const events = frames.filter(f => f.type === 'session/event')
    const byCall = new Map(events
      .filter(f => f.event.type === 'tool/call' || f.event.type === 'tool/result')
      .map(f => [`${f.event.type}:${(f.event.data as { callId: string }).callId}`, f]))

    expect(byCall.get('tool/call:c-gen')?.view).toEqual({ for: 'call', view: { card: 'generic', title: 'gen call' } })
    expect(byCall.get('tool/call:c-term')?.view).toEqual({ for: 'call', view: { card: 'terminal', title: 'echo hi' } })
    expect(byCall.get('tool/call:c-diff')?.view?.view.card).toBe('diff')
    expect(byCall.get('tool/call:c-call-only')?.view).toEqual({
      for: 'call',
      view: { card: 'generic', title: 'program', kind: 'execute', rawInput: 'return value' },
    })
    const callOnlyResult = byCall.get('tool/result:c-call-only')
    expect('view' in (callOnlyResult ?? {})).toBe(false)
    const serializedResult = JSON.stringify(callOnlyResult)
    expect(serializedResult.indexOf(rawResult)).toBeGreaterThanOrEqual(0)
    expect(serializedResult.indexOf(rawResult)).toBe(serializedResult.lastIndexOf(rawResult))
    // No presenter → the frame carries no view property at all.
    expect('view' in (byCall.get('tool/call:c-plain') ?? {})).toBe(false)
    // Throwing presenter → soft-fall: event ships, no view.
    expect(byCall.get('tool/call:c-boom')).toBeDefined()
    expect('view' in (byCall.get('tool/call:c-boom') ?? {})).toBe(false)
    // Result pairing through the live table: presentResult saw the call's args.
    expect(byCall.get('tool/result:c-gen')?.view).toEqual({ for: 'result', view: { card: 'generic', title: 'gen done' } })
  })

  it('serves history entries with call/result views, backscan pairing, and soft-falls', async () => {
    const { ctx } = await harness()
    const api = createApiProxy(ctx, { provider: 'p', model: 'm', cwd: '/tmp', workspaceRoot: '/tmp' })
    const session = ctx.sessions.create()
    // history resolves the agent first; a live structural stub is enough (only
    // .session is read on this path).
    ctx.agents.register({ id: session.id, session, status: 'idle', ctx } as Agent)
    session.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
    session.append('tool/call', { turn: 1, step: 1, callId: CallId('h-term'), name: 'term', arguments: '{"cmd":"ls"}' })
    // meta rides through to presentResult's ToolResult (the spread arm).
    session.append('tool/result', { turn: 1, step: 1, callId: CallId('h-term'), content: [{ type: 'text', text: 'ok' }], isError: false, meta: { n: 1 } }, { surfaceOp: 'append' })
    // Unpaired result: no tool/call with this id anywhere in the page.
    session.append('tool/result', { turn: 1, step: 1, callId: CallId('h-orphan'), content: [{ type: 'text', text: 'x' }], isError: false }, { surfaceOp: 'append' })
    // Paired, but the call's stored arguments do not parse: backscan soft-falls.
    session.append('tool/call', { turn: 1, step: 1, callId: CallId('h-bad'), name: 'term', arguments: '{broken' })
    session.append('tool/result', { turn: 1, step: 1, callId: CallId('h-bad'), content: [{ type: 'text', text: 'y' }], isError: false }, { surfaceOp: 'append' })
    // Presenterless tool: pairing succeeds but presentResult is absent.
    session.append('tool/call', { turn: 1, step: 1, callId: CallId('h-plain'), name: 'plain', arguments: '{}' })
    session.append('tool/result', { turn: 1, step: 1, callId: CallId('h-plain'), content: [{ type: 'text', text: 'z' }], isError: false }, { surfaceOp: 'append' })

    const response = await api.sessions.history({ rpcId: RpcId('t-hist'), payload: { sessionId: session.id } })
    expect(response.result.ok).toBe(true)
    if (!response.result.ok) throw new Error('unreachable')
    const entries = response.result.value.events
    const byKey = new Map(entries
      .filter(entry => entry.event.type === 'tool/call' || entry.event.type === 'tool/result')
      .map(entry => [`${entry.event.type}:${(entry.event.data as { callId: string }).callId}`, entry]))
    expect(byKey.get('tool/call:h-term')?.view).toEqual({ for: 'call', view: { card: 'terminal', title: 'ls' } })
    expect(byKey.get('tool/result:h-term')?.view).toEqual({ for: 'result', view: { card: 'terminal', output: 'done' } })
    expect('view' in (byKey.get('tool/result:h-orphan') ?? {})).toBe(false)
    expect('view' in (byKey.get('tool/result:h-bad') ?? {})).toBe(false)
    expect('view' in (byKey.get('tool/result:h-plain') ?? {})).toBe(false)
  })

  it('tail page carries the full-log todo projection; older pages and todo-less sessions omit it', async () => {
    const { ctx } = await harness()
    const api = createApiProxy(ctx, { provider: 'p', model: 'm', cwd: '/tmp', workspaceRoot: '/tmp' })
    const session = ctx.sessions.create()
    ctx.agents.register({ id: session.id, session, status: 'idle', ctx } as Agent)
    // Superseded write early in the log, latest write later; enough messages to page.
    session.append('todo/write', { todos: [{ content: 'old', status: 'pending' }] })
    for (let turn = 0; turn < 6; turn++) {
      session.append('turn/start', { turn, trigger: { kind: 'message', source: { kind: 'user' } } })
      session.append('user/message', { content: [{ type: 'text', text: `q${turn}` }], source: { kind: 'user' } }, { surfaceOp: 'append' })
      session.append('assistant/message', { turn, step: 0, content: [{ type: 'text', text: `a${turn}` }], provenance: { provider: 'p', model: 'm' } }, { surfaceOp: 'append' })
      session.append('turn/end', { turn, reason: { kind: 'completed' } })
    }
    session.append('todo/write', { todos: [{ content: 'current', status: 'in_progress' }] })

    // Tail page limited to 2 messages: the latest todo/write may or may not sit
    // in the window — the projection must come from the FULL log either way.
    const tail = await api.sessions.history({ rpcId: RpcId('t-todos'), payload: { sessionId: session.id, maxMessages: 2 } })
    if (!tail.result.ok) throw new Error('history failed')
    expect(tail.result.value.todos).toEqual([{ content: 'current', status: 'in_progress' }])
    // An older page omits the projection (session-level, tail-page-only).
    const boundary = tail.result.value.events[0]?.event.seq ?? 0
    const older = await api.sessions.history({ rpcId: RpcId('t-todos-2'), payload: { sessionId: session.id, beforeSeq: boundary, maxMessages: 2 } })
    if (!older.result.ok) throw new Error('older failed')
    expect('todos' in older.result.value).toBe(false)
    // A session with no todo/write anywhere omits the field.
    const bare = ctx.sessions.create()
    ctx.agents.register({ id: bare.id, session: bare, status: 'idle', ctx } as Agent)
    const bareTail = await api.sessions.history({ rpcId: RpcId('t-todos-3'), payload: { sessionId: bare.id } })
    if (!bareTail.result.ok) throw new Error('bare failed')
    expect('todos' in bareTail.result.value).toBe(false)
  })

  it('drops a disposed session from the live open-call table (result after dispose gets no view)', async () => {
    const { ctx } = await harness()
    const api = createApiProxy(ctx, { provider: 'p', model: 'm', cwd: '/tmp', workspaceRoot: '/tmp' })
    const abort = new AbortController()
    const stream = api.events.mux({ rpcId: RpcId('t-mux3'), payload: {} }, abort.signal)

    let session: Session | undefined
    const fiber = await ctx.plugin(Object.assign((inner: Context) => {
      session = inner.sessions.create('session-doomed' as SessionId)
    }, { inject: ['sessions'] }))
    session?.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
    session?.append('tool/call', { turn: 1, step: 1, callId: CallId('c-doomed'), name: 'term', arguments: '{"cmd":"x"}' })
    // Disposing the owning fiber detaches the session mid-stream; the
    // session/disposed listener must clear its open-call table entry.
    await fiber.dispose()

    const frames = await collect(stream, 2, abort)
    const call = frames.find(f => f.type === 'session/event' && f.event.type === 'tool/call')
    expect(call?.type === 'session/event' && call.view?.for).toBe('call')
  })

  it('pairs a result after turn/end via the in-memory backscan fallback', async () => {
    const { ctx } = await harness()
    const api = createApiProxy(ctx, { provider: 'p', model: 'm', cwd: '/tmp', workspaceRoot: '/tmp' })
    const abort = new AbortController()
    const stream = api.events.mux({ rpcId: RpcId('t-mux2'), payload: {} }, abort.signal)
    const collected = collect(stream, 4, abort)

    const session = ctx.sessions.create()
    session.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
    session.append('tool/call', { turn: 1, step: 1, callId: CallId('c-late'), name: 'term', arguments: '{"cmd":"tail"}' })
    session.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
    // The turn/end above cleared the live table; pairing must fall back to
    // scanning the session's in-memory events.
    session.append('tool/result', { turn: 1, step: 1, callId: CallId('c-late'), content: [{ type: 'text', text: 'ok' }], isError: false }, { surfaceOp: 'append' })

    const frames = await collected
    const result = frames.find(f => f.type === 'session/event' && f.event.type === 'tool/result')
    expect(result?.type === 'session/event' && result.view).toEqual({ for: 'result', view: { card: 'terminal', output: 'done' } })
  })
})