package engine

// subagent_silentbug_test.go — validates the silent-bug fix claimed in
// commit bf5c7a7 (2026-04-20, "事件回流 + 生命周期"). That commit asserted —
// but did not empirically verify — that before the refactor, RunSync's
// type switch could never match *TextEvent because sa.runLoop was
// emitting *SubAgentEvent wrappers onto sa's own channel. After the
// switch to bare events on the local channel, RunSync should receive
// *TextEvent directly and accumulate resultTexts.
//
// This test drives sa.RunSync through a scripted provider that emits a
// real *flyto.TextEvent (the block_stop complete-text event, NOT just
// TextDeltaEvent) followed by UsageEvent{StopReason:"end_turn"}. That
// event script is the minimum shape runLoop needs to collect one
// assistant turn and exit cleanly without requiring tool execution.
//
// Passing this test converts the commit-B claim from "inference" to
// "validated". Failing means the silent bug still exists (or was
// misdiagnosed) and requires another fix pass.
//
// subagent_silentbug_test.go — 验证 commit bf5c7a7 (2026-04-20) 声称
// 修复但未实际跑端到端的 silent bug. 该 commit 推断: 重构前 sa.runLoop
// 在本地 channel 发 *SubAgentEvent wrapper, RunSync 的 type switch
// 永远匹配不到 *TextEvent. 重构后本地发 bare 事件, RunSync 应能直接
// 收到 *TextEvent 并累积 resultTexts.
//
// 本测试通过 scripted provider 发出真 *flyto.TextEvent (block_stop
// 完整文本块, 不只是 TextDeltaEvent) + UsageEvent{StopReason:
// "end_turn"}, 这是 runLoop 收完一个 assistant 轮次并干净退出所需的
// 最小事件形状, 不触发工具执行.
//
// 测试通过 = commit B 的声明从"推断"升为"已验证". 测试失败 = silent
// bug 仍存在 (或原诊断有误) 需再次修复.

import (
	"context"
	"strings"
	"testing"
	"time"

	"git.flytoex.net/yuanwei/flyto-agent/pkg/flyto"
	"git.flytoex.net/yuanwei/flyto-agent/pkg/tools"
)

// scriptedProvider emits a preset sequence of flyto events then closes
// the stream. Non-blocking; runs the script in a goroutine and respects
// ctx cancellation between events. Used only by silent-bug tests in
// this file — evolve/llm_adapter_flyto_test.go has its own fakeProvider
// (different package, not shared).
//
// scriptedProvider 按预设脚本发 events 然后关闭 stream. 不阻塞;
// goroutine 内跑脚本, 事件间尊重 ctx 取消. 仅本文件 silent-bug 测试
// 使用 — evolve 包有自己的 fakeProvider (跨包不共享).
type scriptedProvider struct {
	events []flyto.Event
}

func (p *scriptedProvider) Name() string { return "scripted" }

func (p *scriptedProvider) Stream(ctx context.Context, _ *flyto.Request) (<-chan flyto.Event, error) {
	ch := make(chan flyto.Event, len(p.events))
	go func() {
		defer close(ch)
		for _, e := range p.events {
			select {
			case <-ctx.Done():
				return
			case ch <- e:
			}
		}
	}()
	return ch, nil
}

func (p *scriptedProvider) Models(_ context.Context) ([]flyto.ModelInfo, error) {
	return nil, nil
}

// TestSubAgent_RunSync_PropagatesTextEvent is the silent-bug validation
// gate. Drives sa.RunSync against a scripted provider that emits one
// complete text block ("hello") and an end_turn usage event. The bug
// claim is that RunSync's resultTexts accumulator sees zero TextEvents
// when runLoop wraps bare events. If the fix is real, result should
// contain "hello".
//
// TestSubAgent_RunSync_PropagatesTextEvent 是 silent-bug 验证闸. 通过
// scripted provider 发一个完整文本块 ("hello") + end_turn usage 事件
// 驱动 sa.RunSync. bug 声明 = runLoop 包装成 wrapper 时 RunSync 的
// resultTexts 累积看不到 TextEvents. 修复真生效则 result 应含 "hello".
func TestSubAgent_RunSync_PropagatesTextEvent(t *testing.T) {
	cwd := t.TempDir()
	cfg := testConfig()
	cfg.Cwd = cwd
	cfg.Provider = &scriptedProvider{
		events: []flyto.Event{
			&flyto.TextEvent{Text: "hello"},
			&flyto.UsageEvent{StopReason: "end_turn", InputTokens: 1, OutputTokens: 1},
		},
	}
	parent := &Engine{
		cfg:      cfg,
		tools:    tools.NewRegistry(),
		observer: &NoopObserver{},
	}

	sa := SpawnSubAgent(parent, &SubAgentConfig{
		Description: "silent-bug-validation",
		Model:       cfg.Model,
	})

	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
	defer cancel()

	result, err := sa.RunSync(ctx, "hi")
	if err != nil {
		t.Fatalf("RunSync error: %v", err)
	}
	if !strings.Contains(result, "hello") {
		t.Fatalf("RunSync result = %q, want to contain \"hello\"", result)
	}
}