package llm

import "gitea.stevedudenhoeffer.com/steve/go-llm/v2/provider"

// Response represents the result of a completion request.
type Response struct {
	// Text is the assistant's text content. Empty if only tool calls.
	Text string

	// ToolCalls contains any tool invocations the assistant requested.
	ToolCalls []ToolCall

	// Usage contains token usage information (if available from provider).
	Usage *Usage

	// message is the full assistant message for this response.
	message Message
}

// Message returns the full assistant Message for this response,
// suitable for appending to the conversation history.
func (r Response) Message() Message {
	return r.message
}

// HasToolCalls returns true if the response contains tool call requests.
func (r Response) HasToolCalls() bool {
	return len(r.ToolCalls) > 0
}

// Usage captures token consumption.
type Usage struct {
	InputTokens  int
	OutputTokens int
	TotalTokens  int
	Details      map[string]int // provider-specific breakdown (e.g., cached, reasoning tokens)
}

// addUsage merges usage u into the receiver, accumulating token counts and details.
// If the receiver is nil, it returns a copy of u. If u is nil, it returns the receiver unchanged.
func addUsage(total *Usage, u *Usage) *Usage {
	if u == nil {
		return total
	}
	if total == nil {
		cp := *u
		if u.Details != nil {
			cp.Details = make(map[string]int, len(u.Details))
			for k, v := range u.Details {
				cp.Details[k] = v
			}
		}
		return &cp
	}
	total.InputTokens += u.InputTokens
	total.OutputTokens += u.OutputTokens
	total.TotalTokens += u.TotalTokens
	if u.Details != nil {
		if total.Details == nil {
			total.Details = make(map[string]int, len(u.Details))
		}
		for k, v := range u.Details {
			total.Details[k] += v
		}
	}
	return total
}

// Re-export detail key constants from provider package for convenience.
const (
	UsageDetailReasoningTokens     = provider.UsageDetailReasoningTokens
	UsageDetailCachedInputTokens   = provider.UsageDetailCachedInputTokens
	UsageDetailCacheCreationTokens = provider.UsageDetailCacheCreationTokens
	UsageDetailAudioInputTokens    = provider.UsageDetailAudioInputTokens
	UsageDetailAudioOutputTokens   = provider.UsageDetailAudioOutputTokens
	UsageDetailThoughtsTokens      = provider.UsageDetailThoughtsTokens
)