package agent

import (
	"fmt"
	"strings"
	"testing"
)

// TestDiscoveredInstructionsSection：按路径去重、限制总量，并渲染成可读段落。
func TestDiscoveredInstructionsSection(t *testing.T) {
	a := &Agent{}
	a.AddInstructions("/repo/sub/AGENTS.md", "SUB-RULES")
	a.AddInstructions("/repo/sub/AGENTS.md", "SUB-RULES")
	sec := a.InstructionsSection()
	if strings.Count(sec, "SUB-RULES") != 1 {
		t.Fatalf("dedupe failed: %q", sec)
	}
	if !strings.Contains(sec, "discovered for the subtree") || !strings.Contains(sec, "AGENTS.md") {
		t.Fatalf("section shape: %q", sec)
	}

	for i := 0; i < maxDiscoveredFiles+4; i++ {
		a.AddInstructions(fmt.Sprintf("/repo/s%d/AGENTS.md", i), "X")
	}
	if len(a.discoveredInstructions) != maxDiscoveredFiles {
		t.Fatalf("files = %d, want cap %d", len(a.discoveredInstructions), maxDiscoveredFiles)
	}
	if got := a.InstructionsSection(); strings.Count(got, "X") > maxDiscoveredFiles {
		t.Fatalf("cap not applied to rendered section")
	}

	// 空 agent 不产生额外 system 文本。
	empty := &Agent{}
	if got := empty.InstructionsSection(); got != "" {
		t.Fatalf("empty section = %q", got)
	}
}