// Package openai implements the go-llm v2 provider interface for OpenAI.
//
// The actual wire-protocol logic lives in the shared openaicompat package;
// this file encodes OpenAI-specific Rules (temperature is rejected on o-series
// and gpt-5* models) and supplies the default base URL.
package openai

import (
	"strings"

	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/openaicompat"
)

// DefaultBaseURL is the public OpenAI Chat Completions endpoint.
const DefaultBaseURL = "https://api.openai.com/v1"

// Provider is the OpenAI chat-completion provider. It's a type alias over
// openaicompat.Provider so existing callers using openai.Provider keep compiling.
type Provider = openaicompat.Provider

// New creates a new OpenAI provider. An empty baseURL uses DefaultBaseURL.
func New(apiKey string, baseURL string) *Provider {
	if baseURL == "" {
		baseURL = DefaultBaseURL
	}
	return openaicompat.New(apiKey, baseURL, openaicompat.Rules{
		RestrictTemperature: isReasoningModel,
		SupportsReasoning:   isReasoningModel,
	})
}

// isReasoningModel reports whether the named OpenAI model is a reasoning
// model (o-series or gpt-5*). Reasoning models reject a user-supplied
// temperature and accept a reasoning_effort parameter; everything else
// rejects reasoning_effort.
func isReasoningModel(model string) bool {
	return strings.HasPrefix(model, "o") || strings.HasPrefix(model, "gpt-5")
}