// Package agent is the Agent Orchestration bounded context: the agentic
// run loop (prompt -> vLLM -> tool calls -> final reply), the chat-run
// quota/concurrency guard, and the in-flight/just-finished run registry
// that used to live in internal/handlers/chat.go's StreamManager.
//
// This is a saga coordinator, not a data owner: it holds no SQL table of
// its own. It calls billing (usage quota), conversation (persisting
// turns) and knowledge (the search_codebase tool) over gRPC, and
// workspace (every filesystem/bash tool) over gRPC, exactly replacing
// internal/llm/agent.go + internal/llm/tools.go's direct, in-process
// calls into internal/db and the local filesystem.
//
// Rendering (Markdown, syntax highlighting, deliverable cards) stays out
// of this service on purpose — see internal/render's doc comment in the
// gateway service — so this API deals in plain text and structured tool
// results, never HTML.
syntax = "proto3";

package enkly.agent.v1;

option go_package = "enkly/gen/agent/v1;agentv1";

service AgentService {
  // StartTurn replaces the synchronous prefix of Handlers.Chat: the
  // per-user throttle (ChatLimiter), the billing quota check, loading
  // the conversation, persisting the user's prompt, auto-titling, and
  // registering a new run (StreamManager.create) before handing off to
  // a background goroutine. Returns immediately with a stream_id; the
  // reply itself arrives via StreamTurn.
  rpc StartTurn(StartTurnRequest) returns (StartTurnResponse);

  // StreamTurn replaces Handlers.StreamChat: a server-streaming view of
  // one run's progress. resume_from_tool_index mirrors the monolith's
  // SSE Last-Event-ID handling, so a reconnecting client doesn't see
  // tool cards it already has.
  rpc StreamTurn(StreamTurnRequest) returns (stream TurnEvent);

  // StopTurn replaces Handlers.StopStream.
  rpc StopTurn(StopTurnRequest) returns (StopTurnResponse);
}

enum StartTurnOutcome {
  START_TURN_OUTCOME_UNSPECIFIED = 0;
  START_TURN_OUTCOME_OK = 1;
  START_TURN_OUTCOME_CONVERSATION_NOT_FOUND = 2;
  START_TURN_OUTCOME_CONVERSATION_BUSY = 3;
  START_TURN_OUTCOME_TOO_MANY_STREAMS = 4;
  START_TURN_OUTCOME_RATE_LIMITED = 5;
  START_TURN_OUTCOME_QUOTA_EXCEEDED = 6;
  START_TURN_OUTCOME_INTERNAL_ERROR = 7;
}

// SystemEntry is a mid-conversation instruction/permission/budget
// update — see agentrun.SystemEntry (services/agent/internal/
// infrastructure/agentrun/effort.go) for what each kind means and how
// it's folded into the system prompt.
message SystemEntry {
  enum Kind {
    KIND_UNSPECIFIED = 0;
    KIND_INSTRUCTION = 1;
    KIND_PERMISSION = 2;
    KIND_BUDGET = 3;
  }
  Kind kind = 1;
  string content = 2;
}

message StartTurnRequest {
  int64 user_id = 1;
  int64 conversation_id = 2;
  string prompt = 3;

  // --- Fields below this line are the TARGET structured API surface
  // for effort control, fast mode and live system-entry updates — see
  // pkg/turnopts' package doc comment for why they aren't wired up yet
  // (this environment has no protoc/go toolchain to regenerate
  // gen/agent/v1 from this file) and what the working fallback is
  // today (leading /effort, /fast, /system directive lines parsed out
  // of `prompt` itself, by pkg/turnopts.Parse — see
  // application.Service.StartTurn). Once `make proto` is run against
  // this file, a follow-up change points StartTurn at these fields
  // directly, with turnopts kept on as the fallback path for any
  // client that still sends plain-text directives instead. Proto3
  // fields are purely additive and backward compatible to add, so
  // declaring them now costs nothing even before that regeneration —
  // every field below defaults to its zero value for any client built
  // against today's compiled stubs.

  // effort selects one of pkg/effort's five levels ("low", "medium",
  // "high", "extra", "max") for this turn; empty means "use the
  // deployment's configured default" (see agentrun.Agent.Effort).
  string effort = 4;
  // fast_mode requests fast mode for this turn (see
  // application.Service.FastAgent) — available on every plan, unlike
  // dynamic_workflows below.
  bool fast_mode = 5;
  // system_entries are folded into the system prompt for this turn
  // onward (see agentrun.WithSystemEntries) — appended, never
  // replacing anything, so earlier turns' prefix stays stable.
  repeated SystemEntry system_entries = 6;
}

message StartTurnResponse {
  StartTurnOutcome outcome = 1;
  string message = 2;   // user-facing text for any non-OK outcome
  string stream_id = 3; // set when outcome == OK
}

message StreamTurnRequest {
  int64 user_id = 1;
  string stream_id = 2;
  int32 resume_from_tool_index = 3;
}

message ToolCall {
  string name = 1;
  string arguments_json = 2;
  string result = 3;
  bool is_error = 4;
}

// ThinkingRound is one agent round's own reasoning trace, standalone
// rather than folded into the running total thinking_delta carries —
// the same per-step granularity Claude's interleaved thinking exposes
// (one distinct thinking block per tool-use step) rather than one
// cumulative blob for the whole turn. round is 0-indexed and matches
// the round the agent service's internal run loop was on when this
// trace was produced; a client can use it to render reasoning as
// discrete, collapsible steps next to the tool call each one preceded,
// instead of a single growing "thinking" pane.
message ThinkingRound {
  int32 round = 1;
  string thinking = 2;
}

message TurnEvent {
  oneof event {
    string thinking_delta = 1;       // cumulative reasoning text so far, plain
    string token_delta = 2;          // cumulative reply text so far, plain
    ToolCall tool_call = 3;          // one completed tool call
    TurnDone done = 4;
    ThinkingRound thinking_round = 5; // one round's own reasoning trace, standalone
  }
}

message TurnDone {
  string final_text = 1; // plain Markdown source, not yet rendered
  // every tool call made during the turn, successful or not — the
  // gateway uses this to build deliverable (download) cards exactly
  // like internal/handlers/deliverables.go.attachDeliverables.
  repeated ToolCall tool_calls = 2;
}

message StopTurnRequest {
  int64 user_id = 1;
  string stream_id = 2;
}

message StopTurnResponse {}