package llm

import "testing"

func TestEstimateTokensEmpty(t *testing.T) {
	if got := EstimateTokens(nil, nil); got != 0 {
		t.Fatalf("EstimateTokens(nil, nil) = %d, want 0", got)
	}
}

func TestEstimateTokens(t *testing.T) {
	shortMessages := []Message{{Role: RoleUser, Content: "hello"}}
	short := EstimateTokens(shortMessages, nil)
	if short <= 4 {
		t.Fatalf("short estimate = %d, want message framing plus content", short)
	}
	if short > 50 {
		t.Fatalf("short estimate = %d, looks too high for one short message", short)
	}

	longMessages := []Message{
		{Role: RoleUser, Content: "hello"},
		{Role: RoleAssistant, Content: "This is a longer response with enough content to exceed the short estimate."},
	}
	long := EstimateTokens(longMessages, nil)
	if long <= short {
		t.Fatalf("long estimate = %d, want > short estimate %d", long, short)
	}

	withTools := EstimateTokens(shortMessages, []Tool{{
		Type: "function",
		Function: ToolFunction{
			Name:        "file_read",
			Description: "Read a file",
			Parameters:  []byte(`{"type":"object"}`),
		},
	}})
	if withTools <= short {
		t.Fatalf("withTools estimate = %d, want > short estimate %d", withTools, short)
	}

	if msgTokens := estimateMessageTokens(shortMessages[0]); msgTokens <= 4 {
		t.Fatalf("estimateMessageTokens = %d, want message framing plus content", msgTokens)
	}
}