package bot

import (
	"encoding/json"
	"strings"
	"testing"
)

// TestAnthBlockMarshalArglessToolUse pins the echo wire shape: a tool_use the
// model called with NO arguments must round-trip with an explicit empty
// input (the API 400s without it — "tool_use.input: Field required"), while
// other block shapes never grow an input field.
func TestAnthBlockMarshalArglessToolUse(t *testing.T) {
	argless, err := json.Marshal(anthBlock{Type: "tool_use", ID: "tu_1", Name: "issues.list"})
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(argless), `"input":{}`) {
		t.Fatalf("argless tool_use must carry an explicit empty input: %s", argless)
	}

	withArgs, _ := json.Marshal(anthBlock{Type: "tool_use", ID: "tu_2", Name: "fetch",
		Input: map[string]any{"url": "https://a.com/"}})
	if !strings.Contains(string(withArgs), `"url":"https://a.com/"`) {
		t.Fatalf("tool args lost: %s", withArgs)
	}

	for _, b := range []anthBlock{
		{Type: "text", Text: "hi"},
		{Type: "thinking", Thinking: "hmm", Signature: "sig"},
		{Type: "tool_result", ToolUseID: "tu_1", Content: "ok"},
	} {
		out, _ := json.Marshal(b)
		if strings.Contains(string(out), `"input"`) {
			t.Fatalf("%s block grew an input field: %s", b.Type, out)
		}
	}
}

// TestAnthBlockMarshalEmptyThinking pins the other half of the echo trap: a
// ZERO-LENGTH thinking block (adaptive thinking emits these on continuation
// turns — seen live from the read_app_source loop) must round-trip with an
// explicit empty thinking field, or the echo 400s ("thinking.thinking: Field
// required") and the whole reply goes silent. Non-thinking blocks never grow
// the field.
func TestAnthBlockMarshalEmptyThinking(t *testing.T) {
	empty, err := json.Marshal(anthBlock{Type: "thinking", Signature: "sig"})
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(empty), `"thinking":""`) {
		t.Fatalf("empty thinking block must carry an explicit thinking field: %s", empty)
	}
	if !strings.Contains(string(empty), `"signature":"sig"`) {
		t.Fatalf("signature lost from empty thinking block: %s", empty)
	}

	full, _ := json.Marshal(anthBlock{Type: "thinking", Thinking: "hmm", Signature: "sig"})
	if !strings.Contains(string(full), `"thinking":"hmm"`) {
		t.Fatalf("thinking text lost: %s", full)
	}

	for _, b := range []anthBlock{
		{Type: "text", Text: "hi"},
		{Type: "tool_result", ToolUseID: "tu_1", Content: "ok"},
	} {
		out, _ := json.Marshal(b)
		if strings.Contains(string(out), `"thinking"`) {
			t.Fatalf("%s block grew a thinking field: %s", b.Type, out)
		}
	}
}