package loop

import (
	"context"
	"log/slog"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/agent"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/capacity"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/guardrail"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/memory"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/tool"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/trace"
)

// Options configures a Loop. All fields are optional and nil is tolerated until
// the step that actually needs the field: the agent is required for Run (Run
// returns ErrNilAgent otherwise); a missing tool dispatcher causes a requested
// call to be fed back as an error; a missing retriever/persona skips memory
// injection; a missing extractor/store skips the memory hook; a missing
// checkpoint skips persistence; a missing tracer skips tracing.
type Options struct {
	// Agent is the loop's execution unit: an instruction string plus a backend
	// adapter, an optional tool dispatcher and optional guardrails. It is the
	// DEFAULT agent: every turn whose role has no entry in Agents (or every turn
	// when Agents is unset) runs on it, so its instructions should be the global
	// default role's.
	Agent *agent.Agent
	// Agents is the per-role agent pool (design/22 §4.2 方案 A): persona id → the
	// agent carrying that role's system prompt. The loop picks the entry for the
	// turn's resolved role on every step, so switching a session's role switches the
	// prompt without rebuilding the loop (an Agent's instructions are immutable, so
	// one agent per role is the way to keep that invariant). All entries normally
	// share one dispatcher/guardrail pipeline/adapter — only the instructions differ.
	// A missing or nil entry, an unknown role, or an empty pool all fall back to
	// Agent. Nil keeps the pre-existing single-role behavior.
	Agents map[string]*agent.Agent
	// Tools is the tool dispatcher used to execute model-requested calls. When
	// nil the loop falls back to the agent's own dispatcher (if any).
	Tools *tool.Dispatcher
	// Capacity, when non-nil and enabled, filters the tool schemas advertised to
	// the model each round to the allowed set for the current capacity state
	// (design/14 唤醒式能力渐进 §4): the loop only exposes the allowed set to the
	// model — a view, not a hard boundary (Invoke is left unblocked so an
	// emergency call still works). Nil (the default) keeps the pre-existing
	// behavior: every registered tool is advertised.
	Capacity *capacity.Decider
	// OnCapacity, when non-nil, receives capacity_awaken transition events the
	// loop observes while deciding a round (design/14 §4), so a caller can
	// surface the "能力点亮" progression to the frontend. Nil = no-op.
	OnCapacity func(capacity.Event)
	// OnAudit, when non-nil, receives an AuditEvent every time the loop denies a
	// tool call in a restricted (group/stranger) environment (design/11 §3 §8),
	// so the rejection lands in the audit trail and the frontend can render the
	// small "xx 工具在群聊被拒" note. Nil = the rejection is still fed back to the
	// model as a soft not_allowed result, just not recorded to an external sink.
	OnAudit func(AuditEvent)
	// OnTurnEnd, when non-nil, is called once per settled turn (a Run that
	// returned a Result) with the turn's user/assistant text and the persona the
	// loop is bound to, so a caller can advance state that follows the persona —
	// the emotion machine and affection curve of design/01 §2. Its return value
	// is recorded on Result.Mood and carried to the persisted assistant message.
	// Nil = the loop reports nothing and Result.Mood stays empty.
	OnTurnEnd TurnEndHook
	// Memory is the long-term memory store used to persist extracted items.
	Memory *memory.Store
	// Retriever injects relevant memories into the context, re-evaluated every
	// round (see assembleContext) so retrieval tracks the latest conversation.
	Retriever *memory.Retriever
	// WorkingMemory is the per-session sliding window, provided for the
	// orchestrator to inspect; the loop does not mutate it.
	WorkingMemory *memory.WorkingMemory
	// Extractor derives memory items to persist after every step.
	Extractor memory.Extractor
	// Checkpoint persists a durable snapshot of the loop state at every step and,
	// on a later Run with the same sessionID, resumes an interrupted run from it
	// (design §1 durable execution). *persist.Store satisfies the narrow
	// checkpointStore interface; nil disables both persistence and resume.
	Checkpoint checkpointStore
	// Tracer emits a structured span for every step, LLM call and tool call.
	Tracer *trace.Tracer
	// Flow, when non-nil, accumulates the run's trace spans into a per-session
	// flow graph and publishes ws.graph_update on each span transition (design/19
	// §1). Nil disables the realtime flow visualization.
	Flow *FlowPublisher
	// Guards validates request/response payloads on the streaming path, where
	// RunStep is bypassed. On the non-streaming path the agent runs its own
	// guardrails inside RunStep.
	Guards *guardrail.Pipeline
	// PersonaID is the loop's configured role: the global default that every turn
	// without an explicit SessionEnv.PersonaID runs as (design/22 §2 裁决规则 4). It
	// scopes memory retrieval and extraction, the system prompt fallback and the
	// emotion hook. Blank skips memory injection/extraction.
	PersonaID string
	// PersonaKnobs, when non-nil, resolves the reasoning knobs for a role at the
	// start of every request build (design/22 §4.2), so a session bound to role Y
	// uses Y's thinking budget / effort / broadcast switch rather than the default
	// role's. The returned ok=false means "role unknown" and keeps the loop's
	// configured defaults (Options.Thinking / ReasoningEffort / ThinkingShowToUser).
	// Resolving through the role id — rather than a caller-supplied per-turn value —
	// is what keeps every path (gateway, channelbridge, backthink, sub-agents) on the
	// right role's knobs from a single input. Nil keeps the configured defaults for
	// every turn, i.e. the pre-multi-character behavior.
	PersonaKnobs func(personaID string) (LoopKnobs, bool)
	// Timezone is the IANA zone used to render the per-round "current time"
	// system message (e.g. "Asia/Shanghai"). Empty disables time injection
	// entirely (backward compatible); a name that fails to load also disables it.
	Timezone string
	// MaxRounds is the tool-loop upper bound. Non-positive selects
	// DefaultMaxRounds (8).
	MaxRounds int
	// OnStream, when non-nil, switches the loop to the streaming path: the model
	// adapter's ChatStream is driven directly and each structured stream event is
	// forwarded to this callback (model.StreamEvent), so the frontend can render
	// body text, tool calls and (eventually) reasoning segments independently.
	OnStream func(model.StreamEvent)
	// Thinking carries the reasoning knobs (budget / explicit switch) injected
	// into every model request the loop builds when no per-role value overrides it.
	// nil means "do not intervene", which is the pre-existing behavior. It is the
	// DEFAULT for turns whose role has no resolved knobs (Options.PersonaKnobs).
	Thinking *model.Thinking
	// ReasoningEffort is the OpenAI-compatible strength knob injected into every
	// model request. Empty means "do not intervene".
	ReasoningEffort string
	// ThinkingShowToUser gates the thinking frames the loop broadcasts: nil (the
	// default) keeps the pre-existing behavior and pushes them; an explicit false
	// keeps thinking_start/delta/end out of the client stream while text and tool
	// frames are unaffected. The frames are still produced and still reach the
	// model/transcript paths — only the UI broadcast is gated, so display and
	// persistence stay decoupled (design/04 §3.2).
	ThinkingShowToUser *bool
	// ToolExecution selects how a batch of tool calls is run: "parallel" (the
	// default) or "sequential". Empty means parallel.
	ToolExecution string
	// ToolParallelism caps how many tool calls run concurrently when ToolExecution
	// is "parallel". Non-positive selects DefaultToolParallelism (4).
	ToolParallelism int
	// Hooks installs optional per-batch/per-call tool-loop hooks. Every field is
	// nil-tolerant; these are reserved for "敏感操作代审" (design/11) and the
	// future asynchronous-tool path. A zero Hooks value is a no-op.
	Hooks ToolLoopHooks
	// MaxContextTokens is the context budget that triggers overflow compaction.
	// Non-positive (the zero value) disables compaction, preserving the loop's
	// previous behavior. Setting it to a positive value (e.g.
	// DefaultMaxContextTokens) enables compaction: when the loop's estimated
	// context exceeds the budget it summarizes older turns into a leading summary
	// message while keeping the recent tail (including trailing tool results)
	// intact (design §1.3). Nil-tolerant: leaving it unset changes nothing.
	MaxContextTokens int
	// Compactor compacts an over-budget conversation. Nil selects the built-in
	// structural compactor (no model call); a non-nil value lets a caller inject
	// an LLM-backed or custom summarizer. It is only invoked when
	// MaxContextTokens is positive.
	Compactor Compactor
	// Vision, when non-nil, rewrites an image-bearing user message at the start
	// of Run so the main model can reason over the image (design/06 §0). The
	// concrete resolver (vision.MessageResolver) decides via the vision Router
	// whether to keep the image for a vision-capable main model or fold it into a
	// text description from the vision/OCR tool ("先看图再对话"). Nil keeps the
	// image content as-is, passing it through to a vision-capable main model.
	Vision ImageResolver
	// TransformContext, when non-nil, is called immediately before every model
	// step with the assembled message list (after memory injection and any
	// compaction) and the current round number (1-based). It may project, filter
	// or re-order the messages the model sees. It is the loop's equivalent of
	// OpenClaw's transformContext (design §1.3). Nil = no projection.
	TransformContext func(ctx context.Context, messages []model.Message, round int) []model.Message
	// Log is the base logger. Nil is replaced with a discard logger tagged with
	// source "runtime/loop".
	Log *slog.Logger
}