package config

// 本文件承载多供应商 LLM 与其本地第三级的配置块（design/04 §3.1；裁决 03.4.3）。
// 它从 config.go 拆出来有两条理由：config.go 已贴着 AGENTS §10 的 500 行硬上限，
// 而「LLM 各供应商各自的端点/密钥/模型/推理形状」本来就是一块自洽的配置面。

import "strings"

// LLMConfig holds the multi-supplier LLM adapter settings. Provider selects the
// wire protocol; every provider has its own independent base/key/model/fallback
// so multiple vendors can coexist.
type LLMConfig struct {
	// Provider declares which protocol to use: "openai" (OpenAI-compatible
	// /chat/completions) or "anthropic" (Anthropic Messages /v1/messages).
	Provider string `env:"LLM_PROVIDER" default:"openai"`

	// OpenAI-compatible provider (default). Kept flat for backward compatibility
	// with the historic LLM_BASE_URL/API_KEY/MODEL/FALLBACK_MODEL env names.
	BaseURL  string `env:"LLM_BASE_URL"`
	APIKey   string `env:"LLM_API_KEY"`
	Model    string `env:"LLM_MODEL"`
	Fallback string `env:"LLM_FALLBACK_MODEL"`

	// VisionModel is the dedicated model behind the vision tool (image
	// understanding). It is the tool's model, not the main model's ability: the
	// per-persona/per-request routing decision belongs to the vision Router, and
	// the main model's own image input capability is declared by the active
	// models.json group's multimodal flag (裁决 14.4.1/14.4.5)。
	VisionModel string `env:"LLM_VISION_MODEL"`

	// OCRModel is the dedicated model behind the OCR tool. Empty reuses
	// VisionModel, so OCR keeps working without a second endpoint (裁决 14.4.1
	// 的「独立视觉模型 + OCR 模型」)。
	OCRModel string `env:"LLM_OCR_MODEL"`

	// Multimodal 声明**主模型自身**能否收图：models.json 组 `multimodal` 的 env
	// 等价物，只作用于 .env 合成的组，默认 false（语义与分工见 GroupFromEnv）。
	Multimodal bool `env:"LLM_MULTIMODAL" default:"false"`

	// ContextWindow 声明该端点的**模型上下文窗口**（token，LLM_CONTEXT_WINDOW）。
	// 0（默认）表示未声明，此时上下文预算推导回落到
	// config.DefaultModelContextWindow 并记一条 WARN（design/04 附录 A.3）。
	// 负数在 Load 阶段直接报错（窗口没有负数语义）。
	//
	// 它是 models.json 组 `contextWindow` 的 env 等价物（per-group 播种，语义见
	// runtimeconfig.Materialize）；本仓目前没有任何 provider 侧窗口发现代码，
	// 因此窗口是**声明式**的： `GET /models` 的自动发现另立设计。
	ContextWindow int `env:"LLM_CONTEXT_WINDOW"`

	// Local is the optional third degradation level (裁决 03.4.3): primary →
	// fallback → local. It defaults to off because the current machine cannot run
	// a local model comfortably; when off the chain keeps its two-level shape.
	Local LocalLLMConfig

	// FallbackMaxTokens caps the last-resort fallback model in a group's chain
	// (primary → fallback). It is the final safety budget: it only applies when
	// the chain actually has a fallback step, that group sets no per-group
	// MaxTokens (models.json maxTokens) and the request carries no explicit
	// budget. Zero disables the cap (the adapter default then applies).
	FallbackMaxTokens int `env:"LLM_FALLBACK_MAX_TOKENS" default:"8192"`

	// ReasoningKind declares this OpenAI-compatible endpoint's reasoning-switch
	// wire shape (裁决 03.4.2/08.4.1: 不同提供商的开关形状不同，必须逐 provider
	// 独立适配). Values mirror runtimeconfig.ReasoningKind*: "" or "auto" infers
	// the vendor from the model name/base URL and sends nothing when the shape is
	// ambiguous (the conservative default, so an existing .env is unchanged);
	// "deepseek" / "openai" / "vllm" / "dashscope" select that endpoint's shape
	// explicitly. It is the env-fallback twin of the models.json group's
	// `reasoning.kind`, which is the primary carrier (hot-reloadable, panel-edited).
	ReasoningKind string `env:"LLM_REASONING_KIND" default:""`

	// Anthropic native provider, used when Provider=anthropic. Independent
	// config block so each vendor is a self-contained config.
	AnthropicBaseURL  string `env:"ANTHROPIC_BASE_URL"`
	AnthropicAPIKey   string `env:"ANTHROPIC_API_KEY"`
	AnthropicModel    string `env:"ANTHROPIC_MODEL"`
	AnthropicFallback string `env:"ANTHROPIC_FALLBACK_MODEL"`
}

// LocalLLMConfig configures the optional local model rung — the third level of
// the primary → fallback → local degradation chain (裁决 03.4.3). It is opt-in
// and defaults to off: a machine that cannot run a local model comfortably must
// not silently pay for one. It becomes an active chain step only when Enabled is
// true and both BaseURL and Model are set; anything less is reported and skipped
// rather than producing a half-configured step.
type LocalLLMConfig struct {
	// Enabled turns the local rung on. Default false (project red line: 本地模型可开关，默认关).
	Enabled bool `env:"LLM_LOCAL_ENABLED" default:"false"`
	// Provider is the local endpoint's wire protocol: "openai" (llama.cpp /
	// ollama / vLLM compatible endpoints) or "anthropic". Empty means openai.
	Provider string `env:"LLM_LOCAL_PROVIDER" default:"openai"`
	// BaseURL is the local endpoint's base URL (e.g. http://127.0.0.1:8080/v1).
	BaseURL string `env:"LLM_LOCAL_BASE_URL"`
	// APIKey is the local endpoint's key; empty is normal for a local server.
	APIKey string `env:"LLM_LOCAL_API_KEY"`
	// Model is the local model name. Without it the rung stays off.
	Model string `env:"LLM_LOCAL_MODEL"`
}

// Configured reports whether the local rung has enough configuration to act as a
// chain step. Enabled alone is not enough: a missing endpoint or model must not
// become a step that can only fail.
func (l LocalLLMConfig) Configured() bool {
	return l.Enabled && strings.TrimSpace(l.BaseURL) != "" && strings.TrimSpace(l.Model) != ""
}