package agent

import (
	"errors"
	"strings"
	"testing"

	"git.gopher.ink/mirrors2/AutoZero/llm"
)

// TestTruncateSpillSavesAndReferences：截断时把原文落盘并在提示里给出可读路径。
func TestTruncateSpillSavesAndReferences(t *testing.T) {
	long := "HEAD" + strings.Repeat("m", 50000) + "TAIL"
	msgs := []llm.Message{{Role: llm.RoleTool, ToolCallID: "call-1", Content: long}}

	var gotID, gotFull string
	spillFn := func(callID, full string) (string, error) {
		gotID, gotFull = callID, full
		return "/tmp/results/call-1.txt", nil
	}

	view := truncateToolResultsSpill(msgs, 20000, spillFn)

	if gotID != "call-1" {
		t.Errorf("spillFn got callID %q, want call-1", gotID)
	}
	if gotFull != long {
		t.Errorf("spillFn must receive the full original text (got %d bytes, want %d)", len(gotFull), len(long))
	}
	content := view[0].Content
	if !strings.Contains(content, "/tmp/results/call-1.txt") {
		t.Errorf("notice should reference the spilled path:\n%s", content)
	}
	if !strings.Contains(content, "use the read tool") {
		t.Errorf("notice should tell the model how to retrieve it:\n%s", content)
	}
	if !strings.Contains(content, "[truncated") {
		t.Errorf("notice should mention truncation:\n%s", content)
	}
	if len(content) > 20000 {
		t.Errorf("truncated content too long: %d", len(content))
	}
	// transcript（传入的切片）不能被修改。
	if msgs[0].Content != long {
		t.Error("original message must not be mutated")
	}
}

// TestTruncateSpillFailureDegrades：落盘失败时退回"重跑工具"提示，不 panic。
func TestTruncateSpillFailureDegrades(t *testing.T) {
	msgs := []llm.Message{{Role: llm.RoleTool, ToolCallID: "c", Content: strings.Repeat("b", 50000)}}
	view := truncateToolResultsSpill(msgs, 20000, func(_, _ string) (string, error) {
		return "", errors.New("disk full")
	})
	if strings.Contains(view[0].Content, "full output saved") {
		t.Errorf("failed spill must not advertise a path:\n%s", view[0].Content)
	}
	if !strings.Contains(view[0].Content, "narrower query") {
		t.Errorf("failed spill should fall back to the rerun hint:\n%s", view[0].Content)
	}
}