package loop

import (
	"context"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/agent"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
)

// This file owns the loop's per-turn role resolution (DevDocs/design/22 §4.2):
// one process now hosts several roles at once, so everything that used to be read
// off the Loop's construction-time binding — the system prompt (via the agent),
// the memory namespace, the emotion machine and the reasoning knobs — is resolved
// from the turn's SessionEnv instead.
//
// The resolution is deliberately three tiny functions over ctx rather than a
// field on the Loop: the Loop is shared by every concurrent session, so storing a
// resolved role on it would race, while ctx already carries the per-turn env.
// Every role-scoped read must go through these helpers, so prompt, memory,
// emotion and thinking can never disagree about "who is answering".

// LoopKnobs are the per-role model/reasoning knobs injected into every request the
// loop builds. It mirrors the three construction-time options
// (Options.Thinking / Options.ReasoningEffort / Options.ThinkingShowToUser) so a
// caller can resolve them per role while the options keep their meaning as the
// default. A nil Thinking and an empty ReasoningEffort mean "do not intervene",
// and a nil ThinkingShowToUser means "broadcast thinking frames as usual".
type LoopKnobs struct {
	// Thinking is the reasoning directive (budget / explicit switch) for the role.
	Thinking *model.Thinking
	// ReasoningEffort is the OpenAI-compatible strength knob for the role.
	ReasoningEffort string
	// ThinkingShowToUser gates the thinking frames broadcast for the role's turns.
	ThinkingShowToUser *bool
}

// personaFor returns the role the current turn speaks as (design/22 §2): the
// session env's explicit role when the caller resolved one, otherwise the loop's
// configured role (Options.PersonaID, the global default). Both the prompt/memory
// and the emotion hook read it, so a turn can never mix two roles.
func (l *Loop) personaFor(ctx context.Context) string {
	if pid := sessionEnvFrom(ctx).PersonaID; pid != "" {
		return pid
	}
	return l.personaID
}

// agentFor returns the agent that carries the current turn's system prompt: the
// per-role agent pool entry when one exists, otherwise the loop's default agent
// (design/22 §4.2 方案 A). A session bound to a role that has no registered agent —
// an unknown/deleted persona, or a caller that wired no pool — falls back to the
// default agent rather than failing the turn, and its memory scope still follows
// personaFor, so the fallback can never silently re-scope memory.
func (l *Loop) agentFor(ctx context.Context) *agent.Agent {
	if len(l.agents) > 0 {
		if ag := l.agents[l.personaFor(ctx)]; ag != nil {
			return ag
		}
	}
	return l.agent
}

// knobsFor resolves the reasoning knobs for the current turn: the resolver's
// per-role values when it knows the role, otherwise the loop's configured
// defaults. A resolver that does not recognize the role (ok = false) deliberately
// keeps the defaults rather than zeroing the knobs, so an unregistered id behaves
// like the default role instead of silently disabling reasoning.
func (l *Loop) knobsFor(ctx context.Context) LoopKnobs {
	def := LoopKnobs{
		Thinking:           l.thinking,
		ReasoningEffort:    l.reasoningEffort,
		ThinkingShowToUser: l.thinkingShow,
	}
	if l.personaKnobs == nil {
		return def
	}
	pid := l.personaFor(ctx)
	if pid == "" {
		return def
	}
	knobs, ok := l.personaKnobs(pid)
	if !ok {
		return def
	}
	return knobs
}