package llm

import (
	"context"
	"io"
)

type Role string

const (
	RoleSystem    Role = "system"
	RoleUser      Role = "user"
	RoleAssistant Role = "assistant"
)

type Message struct {
	Role    Role   `json:"role"`
	Content string `json:"content"`
}

type ChatRequest struct {
	Model       string    `json:"model"`
	Messages    []Message `json:"messages"`
	Temperature float64   `json:"temperature,omitempty"`
	MaxTokens   int       `json:"max_tokens,omitempty"`
	Stream      bool      `json:"stream"`
}

type ChatResponse struct {
	Content        string `json:"content"`
	Model          string `json:"model"`
	PromptTokens   int    `json:"prompt_tokens"`
	CompletionTokens int  `json:"completion_tokens"`
	TotalTokens    int    `json:"total_tokens"`
	ConversationID string `json:"conversation_id,omitempty"`
}

type StreamDelta struct {
	Content      string `json:"content"`
	FinishReason string `json:"finish_reason,omitempty"`
}

// Provider abstracts an LLM API (OpenAI, Anthropic, etc.)
type Provider interface {
	ChatCompletion(ctx context.Context, req *ChatRequest) (*ChatResponse, error)
	ChatStream(ctx context.Context, req *ChatRequest) (io.ReadCloser, error)
	Name() string
}

type ProviderConfig struct {
	Type    string `json:"type"`
	APIKey  string `json:"api_key"`
	BaseURL string `json:"base_url,omitempty"`
	Model   string `json:"model,omitempty"`
}