Add Ollama SDK with Core Functionality and Documentation

- Introduced the Ollama SDK, providing a comprehensive interface for interacting with Ollama AI models, including text generation, chat conversations, embeddings, and model management.
- Implemented core components such as Client, Config, and various request/response entities to facilitate API interactions.
- Added structured error handling with specific error types for improved clarity and debugging.
- Included a README and usage guide to assist developers in integrating the SDK into their applications, ensuring a smooth onboarding experience.
- Established a fluent API for chat interactions and streaming responses, enhancing usability and flexibility for developers.

pkg/ollama/interfaces.go

@@ -0,0 +1,121 @@
+package ollama
+
+import (
+	"context"
+)
+
+// OllamaService defines the interface for Ollama operations
+type OllamaService interface {
+	// Generate generates text using a specified model and prompt
+	Generate(ctx context.Context, req *GenerateRequest) (*GenerateResponse, error)
+
+	// GenerateWithOptions generates text with additional options
+	GenerateWithOptions(ctx context.Context, req *GenerateRequest, opts *GenerateOptions) (*GenerateResponse, error)
+
+	// Chat performs a conversational chat with the model
+	Chat(ctx context.Context, req *ChatRequest) (*ChatResponse, error)
+
+	// Embed generates embeddings for the given text
+	Embed(ctx context.Context, req *EmbedRequest) (*EmbedResponse, error)
+
+	// PullModel pulls a model from the registry
+	PullModel(ctx context.Context, model string) (*PullResponse, error)
+
+	// ListModels lists available models
+	ListModels(ctx context.Context) (*ListModelsResponse, error)
+
+	// DeleteModel deletes a model
+	DeleteModel(ctx context.Context, model string) (*DeleteResponse, error)
+
+	// ShowModel shows model information
+	ShowModel(ctx context.Context, model string) (*ShowModelResponse, error)
+
+	// Health checks if the Ollama service is available
+	Health(ctx context.Context) error
+
+	// NewChatBuilder creates a new chat builder for conversational interactions
+	NewChatBuilder() ChatBuilder
+}
+
+// HTTPClient defines the interface for HTTP operations
+type HTTPClient interface {
+	// Post performs a POST request
+	Post(ctx context.Context, url string, body interface{}, result interface{}) error
+
+	// Get performs a GET request
+	Get(ctx context.Context, url string, result interface{}) error
+
+	// Delete performs a DELETE request
+	Delete(ctx context.Context, url string, result interface{}) error
+}
+
+// Logger defines the interface for logging operations
+type Logger interface {
+	Debug(msg string, fields map[string]interface{})
+	Info(msg string, fields map[string]interface{})
+	Warn(msg string, fields map[string]interface{})
+	Error(msg string, fields map[string]interface{})
+	Fatal(msg string, fields map[string]interface{})
+	WithFields(fields map[string]interface{}) Logger
+	Sync() error
+}
+
+// ChatBuilder provides a fluent interface for building chat requests
+type ChatBuilder interface {
+	// SetModel sets the model to use
+	SetModel(model string) ChatBuilder
+
+	// SetSystem sets the system prompt
+	SetSystem(system string) ChatBuilder
+
+	// AddMessage adds a message to the conversation
+	AddMessage(role MessageRole, content string) ChatBuilder
+
+	// SetTemperature sets the temperature for generation
+	SetTemperature(temperature float64) ChatBuilder
+
+	// SetTopP sets the top_p parameter
+	SetTopP(topP float64) ChatBuilder
+
+	// SetMaxTokens sets the maximum number of tokens to generate
+	SetMaxTokens(maxTokens int) ChatBuilder
+
+	// SetStream sets whether to stream the response
+	SetStream(stream bool) ChatBuilder
+
+	// SetFormat sets the response format
+	SetFormat(format string) ChatBuilder
+
+	// SetOptions sets custom options
+	SetOptions(options map[string]interface{}) ChatBuilder
+
+	// Build creates the chat request
+	Build() (*ChatRequest, error)
+
+	// Send builds and sends the chat request
+	Send(ctx context.Context) (*ChatResponse, error)
+
+	// Continue continues the conversation with the current context
+	Continue(ctx context.Context, userMessage string) (*ChatResponse, error)
+}
+
+// MessageRole represents the role of a message in a chat
+type MessageRole string
+
+const (
+	MessageRoleSystem    MessageRole = "system"
+	MessageRoleUser      MessageRole = "user"
+	MessageRoleAssistant MessageRole = "assistant"
+)
+
+// GenerateOptions represents additional options for text generation
+type GenerateOptions struct {
+	Temperature   *float64               `json:"temperature,omitempty"`
+	TopP          *float64               `json:"top_p,omitempty"`
+	TopK          *int                   `json:"top_k,omitempty"`
+	RepeatPenalty *float64               `json:"repeat_penalty,omitempty"`
+	Seed          *int                   `json:"seed,omitempty"`
+	Stop          []string               `json:"stop,omitempty"`
+	Format        string                 `json:"format,omitempty"`
+	Options       map[string]interface{} `json:"options,omitempty"`
+}