package main

import (
	"git.yeij.top/AskaEth/Cyrene_v2/internal/logger"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/agent"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/guardrail"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/tool"
)

// This file builds the per-role agent pool (design/22 §4.2 方案 A). An
// agent.Agent's instructions are immutable after construction, so "the session's
// role decides the system prompt" is implemented as one agent per role, all
// sharing the same dispatcher, guardrail pipeline, model adapter and options —
// only the instruction string differs. The loop picks the pool entry for the
// turn's role on every step (internal/runtime/loop/persona.go), so a role switch
// takes effect on the next turn without rebuilding the loop.
//
// Requirements from design/22 §5: prompt, memory, emotion and thinking must all
// be resolved from the same role. The pool owns the prompt; the loop owns the
// other three (personaFor / knobsFor), so a turn can never mix two roles.

// personaAgentPool returns the per-role agent pool plus the agent to run turns
// with: the pooled agent for the default role when the pool has one, otherwise the
// caller's fallback agent, so a deployment with no registered character keeps
// exactly the pre-multi-character single agent.
func (a *app) personaAgentPool(llm *model.RuntimeLLM, dispatcher *tool.Dispatcher, guards *guardrail.Pipeline, fallback *agent.Agent) (map[string]*agent.Agent, *agent.Agent) {
	pool := a.buildPersonaAgents(llm, dispatcher, guards)
	if pooled, ok := pool[a.defaultPersonaID()]; ok {
		return pool, pooled
	}
	return pool, fallback
}

// buildPersonaAgents returns the role → agent pool: every registered character's
// persona gets an agent carrying that persona's system instruction
// (instructionsFromPersona, the very same assembly point as the default agent —
// see personaInstructions), design/01 §2.2. It returns an empty map when no
// persona is registered, so the loop keeps its single default agent.
//
// 池里的指令是**静态**的，因此主人身份说明书不在其中：那段知识按会话注入
// （loop.Options.PersonaKnowledgeFor），否则它会跟着每个角色进入群聊与
// 陌生人私聊（design/11 §0 红线）。
//
// Only personas reachable through a registered character are pooled: a character
// is the selectable unit (1 character ↔ 1 persona), so a persona with no character
// can never be bound to a session. A session bound to an unknown id therefore
// falls back to the default agent, and its memory scope still follows the bound
// id — a stale binding degrades to the default prompt rather than failing the
// turn.
func (a *app) buildPersonaAgents(llm *model.RuntimeLLM, dispatcher *tool.Dispatcher, guards *guardrail.Pipeline) map[string]*agent.Agent {
	log := logger.WithSource(a.log, "cmd/cyrene")
	pool := make(map[string]*agent.Agent, a.personas.CountPersonas())
	for _, c := range a.personas.List() {
		if _, ok := pool[c.PersonaID]; ok {
			continue
		}
		p, ok := a.personas.Persona(c.PersonaID)
		if !ok || p == nil {
			continue
		}
		// 该角色的 agent 必须绑它自己的 persona 视图：否则 models.json 的 personaModels /
		// personaProviders（角色级模型/提供商路由）在生产里不会被消费，形同虚设。
		stack := llm.ForPersona(c.PersonaID)
		ag, err := agent.New(a.personaInstructions(p), dispatcher, guards,
			agent.WithModel(stack, stack),
			agent.WithOptions(agent.Options{MaxRounds: defaultMaxRounds, Purpose: "chat"}))
		if err != nil {
			log.Warn("persona agent skipped", "persona", c.PersonaID, "error", err)
			continue
		}
		pool[c.PersonaID] = ag
	}
	return pool
}

// personaExists returns the resolver the orchestration layer validates a dispatched
// sub-agent's target role with (design/22 §8-2). A role is dispatchable exactly when
// the pool has an agent for it, which is precisely the condition under which the loop
// would answer with that role's instructions. Every other answer — an unregistered
// persona, a persona with no character, an empty pool — makes the dispatch fail with
// orchestration.ErrUnknownPersona instead of quietly running the sub-agent as the
// default role.
func personaExists(pool map[string]*agent.Agent) func(personaID string) bool {
	return func(personaID string) bool {
		_, ok := pool[personaID]
		return ok
	}
}