package orchestration

import (
	"context"
	"fmt"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/loop"
)

// This file owns the "派出去的子代理以目标角色身份运行" half of design/22 §8-2: a
// sub-agent dispatched with a target persona must answer with that role's
// instructions and use that role's memory scope, and a role this process cannot run
// must be rejected loudly instead of silently degrading into the default role.
//
// The resolution itself stays in the loop (internal/runtime/loop/persona.go): every
// role-scoped read — prompt (agent pool), memory namespace, emotion, thinking knobs
// — is derived from the session env's PersonaID, one input, so the four can never
// disagree. The orchestration layer therefore has exactly two jobs: validate the id,
// and stamp it onto the sub-agent's run context. Neither touches the identity lane
// (ActorEnv / MemWritable), which is decided structurally by the channel layer and
// is never a persona's business (project red line: 身份识别靠元数据).

// PersonaKnown reports whether personaID is a role this process can run with its
// own instructions (Options.PersonaExists). A blank id is trivially known: the
// caller is naming no role, which is the pre-existing single-role dispatch. A nil
// resolver makes every named role unknown, so a role-naming dispatch fails instead
// of quietly running as the default role.
func (s *Scheduler) PersonaKnown(personaID string) bool {
	return personaID == "" || (s.personaExists != nil && s.personaExists(personaID))
}

// effectiveRole returns the role to record on the sub-agent as its binding. A
// dispatched persona IS the binding (the sub-agent answers as that role), so it fills
// a blank RoleID; an explicit RoleID that names no persona is left as the caller set
// it. The recorded role is what the progress events and the ws subagent_event frame
// report, so the frontend never shows a sub-agent running as yuki with an empty role.
func effectiveRole(spec AgentSpec) string {
	if spec.RoleID == "" {
		return spec.PersonaID
	}
	return spec.RoleID
}

// checkPersona rejects a role the process cannot run, wrapping ErrUnknownPersona so
// a caller can classify it with errors.Is.
func (s *Scheduler) checkPersona(personaID string) error {
	if s.PersonaKnown(personaID) {
		return nil
	}
	return fmt.Errorf("orchestration: spawn: persona %q: %w", personaID, ErrUnknownPersona)
}

// CheckPersonas validates every spec's target role before a batch is spawned, so one
// unknown id rejects the whole dispatch instead of leaving the earlier sub-agents of
// the batch running with no result ever reported. The dispatch tool calls it right
// after decoding the arguments, where the ids are known but nothing has started yet.
func (s *Scheduler) CheckPersonas(specs []AgentSpec) error {
	for _, spec := range specs {
		if err := s.checkPersona(spec.PersonaID); err != nil {
			return err
		}
	}
	return nil
}

// withPersonaEnv returns ctx with the target role stamped onto the session env, so
// the loop resolves that role's prompt and memory scope for every step of the
// sub-agent's run. The rest of the env (the identity lane and the memory-write gate)
// is copied unchanged — a persona decides how she answers, never what she may touch.
// A blank id returns ctx untouched, so a persona-less dispatch keeps inheriting the
// spawning turn's env exactly as before.
func withPersonaEnv(ctx context.Context, personaID string) context.Context {
	if personaID == "" {
		return ctx
	}
	env := loop.SessionEnvFrom(ctx)
	env.PersonaID = personaID
	return loop.WithSessionEnv(ctx, env)
}