package vllmkit

// Role, Message, ToolCallRequest and ToolDef are local equivalents of
// the monolith's internal/models types — kept here, scoped to exactly
// what the OpenAI-compatible chat-completions wire protocol vLLM
// serves needs, so this package has no dependency beyond the Go
// standard library. The agent service (the only caller of ChatStream)
// translates its own domain messages to and from these at the
// boundary; see services/agent/internal/infrastructure/agentrun.
type Role string

const (
	RoleUser      Role = "user"
	RoleAssistant Role = "assistant"
	RoleSystem    Role = "system"
	RoleTool      Role = "tool"
)

// Message is one turn in a conversation, as sent to/received from
// vLLM's OpenAI-compatible /v1/chat/completions endpoint.
type Message struct {
	Role     Role
	Content  string
	ToolName string
	Thinking string // reasoning trace (OpenAI wire: "reasoning_content"); sent back to the model, never persisted

	// ToolCalls is set on an assistant message that requested one or
	// more tool invocations — see ToolCallRequest.
	ToolCalls []ToolCallRequest

	// ToolCallID identifies, on a role="tool" message, which of the
	// preceding assistant message's ToolCalls this is the result for.
	// The OpenAI tool-calling contract requires every tool message to
	// carry the matching call's id (unlike Ollama's native /api/chat,
	// which correlated tool replies positionally with no id at all) —
	// vLLM's tool-call parsers (hermes, llama3-json, qwen, …) reject a
	// tool message with a missing/mismatched tool_call_id outright, so
	// this must be populated whenever Role == RoleTool. Callers get it
	// for free: ToolCallRequest.ID below is populated straight off the
	// id vLLM assigned the call, and ToolResult carries it forward
	// unchanged — see agentrun.Agent.Run, which copies
	// ToolCallRequest.ID into the ToolResult it builds and then into
	// this field when it appends the reply message.
	ToolCallID string
}

// ToolCallRequest is a single tool invocation the model asked for. ID
// is the id vLLM's response assigned the call (OpenAI wire:
// tool_calls[].id) — callers must echo it back as ToolResult's
// ToolCallID so the follow-up tool message can carry Message.ToolCallID.
type ToolCallRequest struct {
	ID        string
	Name      string
	Arguments map[string]any
}

// ToolResult is what gets fed back to the model after executing a
// ToolCallRequest.
type ToolResult struct {
	ToolCallID string
	Name       string
	Content    string
	IsError    bool
}

// ToolDef describes a single callable tool in the JSON-schema shape
// the OpenAI-compatible function-calling API (and therefore vLLM)
// expects.
type ToolDef struct {
	Name        string
	Description string
	Parameters  map[string]any // JSON Schema object
}