package llm

import (
	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/deepseek"
	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/groq"
	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/moonshot"
	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/ollama"
	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/openai"
	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/xai"
)

// ProviderInfo describes a registered provider for discovery purposes (CLI
// pickers, wiring layers, admin tools). It is the single source of truth for
// "what providers exist and how do I instantiate one."
type ProviderInfo struct {
	// Name is the short lowercase identifier used in provider/model strings
	// (e.g., "openai", "deepseek", "moonshot").
	Name string

	// DisplayName is a human-readable label for UIs.
	DisplayName string

	// EnvKey is the conventional environment variable that holds the API key
	// for this provider. Empty string means "no key needed" (e.g., Ollama).
	EnvKey string

	// DefaultURL is the default base URL used when no override is supplied.
	DefaultURL string

	// Models is a list of well-known model names, populated for CLI pickers
	// and similar. It is not exhaustive and not validated against the API.
	Models []string

	// New returns a ready-to-use Client for this provider, given an API key
	// (ignored for key-less providers like Ollama) and optional ClientOptions.
	New func(apiKey string, opts ...ClientOption) *Client
}

// providerRegistry is the in-process list of known providers. Order is
// intentional: the three original providers first, then OpenAI-compatible
// additions in the order they were added.
var providerRegistry = []ProviderInfo{
	{
		Name:        "openai",
		DisplayName: "OpenAI",
		EnvKey:      "OPENAI_API_KEY",
		DefaultURL:  openai.DefaultBaseURL,
		Models: []string{
			"gpt-4.1", "gpt-4.1-mini", "gpt-4.1-nano",
			"gpt-4o", "gpt-4o-mini",
			"gpt-4-turbo", "gpt-3.5-turbo",
			"o1", "o1-mini", "o1-preview", "o3-mini",
		},
		New: OpenAI,
	},
	{
		Name:        "anthropic",
		DisplayName: "Anthropic",
		EnvKey:      "ANTHROPIC_API_KEY",
		DefaultURL:  "https://api.anthropic.com",
		Models: []string{
			"claude-opus-4-7",
			"claude-sonnet-4-6",
			"claude-haiku-4-5-20251001",
			"claude-opus-4-20250514",
			"claude-sonnet-4-20250514",
			"claude-3-7-sonnet-20250219",
			"claude-3-5-sonnet-20241022",
			"claude-3-5-haiku-20241022",
		},
		New: Anthropic,
	},
	{
		Name:        "google",
		DisplayName: "Google",
		EnvKey:      "GOOGLE_API_KEY",
		DefaultURL:  "https://generativelanguage.googleapis.com",
		Models: []string{
			"gemini-2.0-flash", "gemini-2.0-flash-lite",
			"gemini-1.5-pro", "gemini-1.5-flash", "gemini-1.5-flash-8b",
		},
		New: Google,
	},
	{
		Name:        "deepseek",
		DisplayName: "DeepSeek",
		EnvKey:      "DEEPSEEK_API_KEY",
		DefaultURL:  deepseek.DefaultBaseURL,
		Models:      []string{"deepseek-chat", "deepseek-reasoner"},
		New:         DeepSeek,
	},
	{
		Name:        "moonshot",
		DisplayName: "Moonshot (Kimi)",
		EnvKey:      "MOONSHOT_API_KEY",
		DefaultURL:  moonshot.DefaultBaseURL,
		Models: []string{
			"kimi-k2-0711-preview",
			"moonshot-v1-8k", "moonshot-v1-32k", "moonshot-v1-128k",
			"moonshot-v1-8k-vision-preview",
		},
		New: Moonshot,
	},
	{
		Name:        "xai",
		DisplayName: "xAI (Grok)",
		EnvKey:      "XAI_API_KEY",
		DefaultURL:  xai.DefaultBaseURL,
		Models: []string{
			"grok-2", "grok-2-mini", "grok-2-vision", "grok-beta",
		},
		New: XAI,
	},
	{
		Name:        "groq",
		DisplayName: "Groq",
		EnvKey:      "GROQ_API_KEY",
		DefaultURL:  groq.DefaultBaseURL,
		Models: []string{
			"llama-3.3-70b-versatile",
			"llama-3.1-8b-instant",
			"mixtral-8x7b-32768",
			"gemma2-9b-it",
			"llama-3.2-90b-vision-preview",
		},
		New: Groq,
	},
	{
		Name:        "ollama",
		DisplayName: "Ollama (local)",
		EnvKey:      "", // no key needed
		DefaultURL:  ollama.DefaultBaseURL,
		Models: []string{
			"llama3.2", "llama3.1", "qwen2.5", "mistral", "gemma2", "phi4",
		},
		New: func(_ string, opts ...ClientOption) *Client { return Ollama(opts...) },
	},
}

// Providers returns a copy of the registered provider list so callers cannot
// mutate library state.
func Providers() []ProviderInfo {
	out := make([]ProviderInfo, len(providerRegistry))
	copy(out, providerRegistry)
	return out
}

// ProviderByName returns the registered ProviderInfo with the given name, or
// nil if no such provider is registered. Name matching is exact.
func ProviderByName(name string) *ProviderInfo {
	for i := range providerRegistry {
		if providerRegistry[i].Name == name {
			p := providerRegistry[i]
			return &p
		}
	}
	return nil
}