server/llm/llm.go

package llm

import (
	"context"
	"time"
)

// LLMProvider defines the interface that all LLM providers must implement
type LLMProvider interface {
	// ChatCompletion creates a chat completion
	ChatCompletion(ctx context.Context, req ChatCompletionRequest) (*ChatCompletionResponse, error)

	// CreateEmbeddings generates embeddings for the given input
	CreateEmbeddings(ctx context.Context, req EmbeddingRequest) (*EmbeddingResponse, error)

	// Close performs any necessary cleanup
	Close() error
}

// ProviderFactory creates LLM provider instances
type ProviderFactory interface {
	// CreateProvider creates a new LLM provider instance
	CreateProvider(config Config) (LLMProvider, error)

	// SupportsProvider checks if the factory supports the given provider
	SupportsProvider(provider Provider) bool
}

// Provider represents different LLM service providers
type Provider string

const (
	ProviderOpenAI Provider = "openai"
	ProviderXAI    Provider = "xai"
	ProviderClaude Provider = "claude"
	ProviderGemini Provider = "gemini"
	ProviderLocal  Provider = "local"
	ProviderFake   Provider = "fake"
)

// Role represents the role of a message participant
type Role string

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

// Message represents a single message in a conversation
type Message struct {
	Role       Role       `json:"role"`
	Content    string     `json:"content"`
	ToolCalls  []ToolCall `json:"tool_calls,omitempty"`
	ToolCallID string     `json:"tool_call_id,omitempty"`
	Name       string     `json:"name,omitempty"`
}

// ToolCall represents a function/tool call request
type ToolCall struct {
	ID       string   `json:"id"`
	Type     string   `json:"type"`
	Function Function `json:"function"`
}

// Function represents a function definition
type Function struct {
	Name        string                 `json:"name"`
	Description string                 `json:"description,omitempty"`
	Parameters  map[string]interface{} `json:"parameters,omitempty"`
}

// Tool represents a tool that can be called by the model
type Tool struct {
	Type     string   `json:"type"`
	Function Function `json:"function"`
}

// ChatCompletionRequest represents a request to complete a chat conversation
type ChatCompletionRequest struct {
	Model            string                 `json:"model"`
	Messages         []Message              `json:"messages"`
	MaxTokens        *int                   `json:"max_tokens,omitempty"`
	Temperature      *float64               `json:"temperature,omitempty"`
	TopP             *float64               `json:"top_p,omitempty"`
	N                *int                   `json:"n,omitempty"`
	Stream           *bool                  `json:"stream,omitempty"`
	Stop             []string               `json:"stop,omitempty"`
	PresencePenalty  *float64               `json:"presence_penalty,omitempty"`
	FrequencyPenalty *float64               `json:"frequency_penalty,omitempty"`
	LogitBias        map[string]int         `json:"logit_bias,omitempty"`
	User             string                 `json:"user,omitempty"`
	Tools            []Tool                 `json:"tools,omitempty"`
	ToolChoice       interface{}            `json:"tool_choice,omitempty"`
	ResponseFormat   *ResponseFormat        `json:"response_format,omitempty"`
	Seed             *int64                 `json:"seed,omitempty"`
	ExtraParams      map[string]interface{} `json:"-"` // For provider-specific parameters
}

// ResponseFormat specifies the format of the response
type ResponseFormat struct {
	Type string `json:"type"` // "text" or "json_object"
}

// ChatCompletionResponse represents a response from a chat completion request
type ChatCompletionResponse struct {
	ID                string                 `json:"id"`
	Object            string                 `json:"object"`
	Created           int64                  `json:"created"`
	Model             string                 `json:"model"`
	SystemFingerprint string                 `json:"system_fingerprint,omitempty"`
	Choices           []ChatCompletionChoice `json:"choices"`
	Usage             Usage                  `json:"usage"`
	Provider          Provider               `json:"provider"`
}

// ChatCompletionChoice represents a single choice in a chat completion response
type ChatCompletionChoice struct {
	Index        int                    `json:"index"`
	Message      Message                `json:"message"`
	Logprobs     *Logprobs              `json:"logprobs,omitempty"`
	FinishReason string                 `json:"finish_reason"`
	Delta        *Message               `json:"delta,omitempty"` // For streaming
	ExtraData    map[string]interface{} `json:"-"`               // For provider-specific data
}

// Logprobs represents log probability information
type Logprobs struct {
	Content []LogprobContent `json:"content,omitempty"`
}

// LogprobContent represents content with log probabilities
type LogprobContent struct {
	Token       string       `json:"token"`
	Logprob     float64      `json:"logprob"`
	Bytes       []int        `json:"bytes,omitempty"`
	TopLogprobs []TopLogprob `json:"top_logprobs,omitempty"`
}

// TopLogprob represents a top log probability
type TopLogprob struct {
	Token   string  `json:"token"`
	Logprob float64 `json:"logprob"`
	Bytes   []int   `json:"bytes,omitempty"`
}

// Usage represents token usage information
type Usage struct {
	PromptTokens     int `json:"prompt_tokens"`
	CompletionTokens int `json:"completion_tokens"`
	TotalTokens      int `json:"total_tokens"`
}

// EmbeddingRequest represents a request to generate embeddings
type EmbeddingRequest struct {
	Input          interface{}            `json:"input"` // string, []string, or []int
	Model          string                 `json:"model"`
	EncodingFormat string                 `json:"encoding_format,omitempty"`
	Dimensions     *int                   `json:"dimensions,omitempty"`
	User           string                 `json:"user,omitempty"`
	ExtraParams    map[string]interface{} `json:"-"` // For provider-specific parameters
}

// EmbeddingResponse represents a response from an embedding request
type EmbeddingResponse struct {
	Object   string      `json:"object"`
	Data     []Embedding `json:"data"`
	Usage    Usage       `json:"usage"`
	Model    string      `json:"model"`
	Provider Provider    `json:"provider"`
}

// Embedding represents a single embedding
type Embedding struct {
	Object    string    `json:"object"`
	Embedding []float64 `json:"embedding"`
	Index     int       `json:"index"`
}

// ModelInfo represents information about an available model
type ModelInfo struct {
	ID         string                 `json:"id"`
	Object     string                 `json:"object"`
	Created    int64                  `json:"created"`
	OwnedBy    string                 `json:"owned_by"`
	Permission []ModelPermission      `json:"permission"`
	Root       string                 `json:"root"`
	Parent     string                 `json:"parent"`
	Provider   Provider               `json:"provider"`
	ExtraData  map[string]interface{} `json:"-"` // For provider-specific data
}

// ModelPermission represents permissions for a model
type ModelPermission struct {
	ID                 string `json:"id"`
	Object             string `json:"object"`
	Created            int64  `json:"created"`
	AllowCreateEngine  bool   `json:"allow_create_engine"`
	AllowSampling      bool   `json:"allow_sampling"`
	AllowLogprobs      bool   `json:"allow_logprobs"`
	AllowSearchIndices bool   `json:"allow_search_indices"`
	AllowView          bool   `json:"allow_view"`
	AllowFineTuning    bool   `json:"allow_fine_tuning"`
	Organization       string `json:"organization"`
	Group              string `json:"group"`
	IsBlocking         bool   `json:"is_blocking"`
}

// Error represents an error response from an LLM provider
type Error struct {
	Error struct {
		Message string `json:"message"`
		Type    string `json:"type"`
		Code    string `json:"code,omitempty"`
		Param   string `json:"param,omitempty"`
	} `json:"error"`
}

// Config represents configuration for an LLM provider
type Config struct {
	Provider    Provider               `json:"provider"`
	APIKey      string                 `json:"api_key"`
	BaseURL     string                 `json:"base_url,omitempty"`
	Timeout     time.Duration          `json:"timeout,omitempty"`
	MaxRetries  int                    `json:"max_retries,omitempty"`
	ExtraConfig map[string]interface{} `json:"extra_config,omitempty"`
}

// StreamResponse represents a streaming response chunk
type StreamResponse struct {
	ID                string                 `json:"id"`
	Object            string                 `json:"object"`
	Created           int64                  `json:"created"`
	Model             string                 `json:"model"`
	SystemFingerprint string                 `json:"system_fingerprint,omitempty"`
	Choices           []ChatCompletionChoice `json:"choices"`
	Usage             *Usage                 `json:"usage,omitempty"`
	Provider          Provider               `json:"provider"`
}

// DefaultConfigs provides default configurations for different providers
var DefaultConfigs = map[Provider]Config{
	ProviderOpenAI: {
		Provider:   ProviderOpenAI,
		BaseURL:    "https://api.openai.com/v1",
		Timeout:    30 * time.Second,
		MaxRetries: 3,
	},
	ProviderXAI: {
		Provider:   ProviderXAI,
		BaseURL:    "https://api.x.ai/v1",
		Timeout:    30 * time.Second,
		MaxRetries: 3,
	},
	ProviderClaude: {
		Provider:   ProviderClaude,
		BaseURL:    "https://api.anthropic.com/v1",
		Timeout:    30 * time.Second,
		MaxRetries: 3,
	},
	ProviderGemini: {
		Provider:   ProviderGemini,
		BaseURL:    "https://generativelanguage.googleapis.com/v1",
		Timeout:    30 * time.Second,
		MaxRetries: 3,
	},
	ProviderLocal: {
		Provider:   ProviderLocal,
		BaseURL:    "http://localhost:11434",
		Timeout:    60 * time.Second,
		MaxRetries: 1,
	},
	ProviderFake: {
		Provider:   ProviderFake,
		BaseURL:    "fake://test",
		Timeout:    1 * time.Second,
		MaxRetries: 0,
	},
}