feat: bootstrap goaichat CLI and config system

internal/openai/types.go

@@ -0,0 +1,51 @@
+package openai
+
+// ChatMessage represents a single message within a chat completion request or response.
+type ChatMessage struct {
+	Role    string `json:"role"`
+	Content string `json:"content"`
+}
+
+// ChatCompletionRequest encapsulates the payload for the OpenAI Chat Completions API.
+type ChatCompletionRequest struct {
+	Model       string        `json:"model"`
+	Messages    []ChatMessage `json:"messages"`
+	MaxTokens   *int          `json:"max_tokens,omitempty"`
+	Temperature *float64      `json:"temperature,omitempty"`
+	Stream      bool          `json:"stream,omitempty"`
+}
+
+// ChatCompletionChoice captures an individual response choice returned from the API.
+type ChatCompletionChoice struct {
+	Index        int         `json:"index"`
+	Message      ChatMessage `json:"message"`
+	FinishReason string      `json:"finish_reason"`
+}
+
+// Usage captures token accounting for a chat completion call.
+type Usage struct {
+	PromptTokens     int `json:"prompt_tokens"`
+	CompletionTokens int `json:"completion_tokens"`
+	TotalTokens      int `json:"total_tokens"`
+}
+
+// ChatCompletionResponse represents the top-level response payload from the API.
+type ChatCompletionResponse struct {
+	ID      string                 `json:"id"`
+	Object  string                 `json:"object"`
+	Choices []ChatCompletionChoice `json:"choices"`
+	Usage   Usage                  `json:"usage"`
+}
+
+// APIError captures structured error responses returned by the API.
+type APIError struct {
+	Message string `json:"message"`
+	Type    string `json:"type"`
+	Param   string `json:"param"`
+	Code    any    `json:"code"`
+}
+
+// ErrorResponse is returned on non-2xx responses.
+type ErrorResponse struct {
+	Error APIError `json:"error"`
+}