package orchestration

import (
	"errors"
	"strings"

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

// Status is the lifecycle state of a spawned sub-agent.
//
// The lifecycle is pending -> running -> one of the terminal states
// (done, failed, aborted). A sub-agent is terminal exactly when Terminal
// reports true.
type Status string

const (
	// StatusPending means the sub-agent was created but has not started.
	StatusPending Status = "pending"
	// StatusRunning means the sub-agent's loop is executing.
	StatusRunning Status = "running"
	// StatusDone means the loop completed and produced a result.
	StatusDone Status = "done"
	// StatusFailed means the loop returned an error.
	StatusFailed Status = "failed"
	// StatusAborted means the sub-agent was canceled or timed out.
	StatusAborted Status = "aborted"
)

// Terminal reports whether s is a final state. Pending and running are not
// terminal; every sub-agent ends in one of the three terminal states.
func (s Status) Terminal() bool {
	return s == StatusDone || s == StatusFailed || s == StatusAborted
}

// AgentSpec describes a sub-agent to spawn. Goal is required; the rest are
// optional and bound onto the sub-agent for the upper layer to interpret.
type AgentSpec struct {
	// Goal is the objective the sub-agent works toward. It is required.
	Goal string
	// RoleID selects the role/persona the sub-agent is bound to.
	RoleID string
	// Mode selects the behavior mode (e.g. "engineer") for the role.
	Mode string
	// Context is the initial, isolated conversation context. Spawn deep-copies
	// it, so later mutation by the caller does not affect the sub-agent.
	Context []model.Message
	// AttachInfo is free-form attachment/injection text supplied at spawn.
	AttachInfo string
	// Data carries an optional structured payload for the caller's use.
	Data any
}

// Progress event names published on the agent-to-agent bus via the Scheduler's
// comm probe. External subscribers can match on these to drive a monitoring
// panel (DevDocs/design/05-子代理.md §9).
const (
	// EventDispatched is published when a sub-agent is created.
	EventDispatched = "subagent.dispatched"
	// EventStarted is published when a sub-agent begins running.
	EventStarted = "subagent.started"
	// EventDone is published when a sub-agent finishes successfully.
	EventDone = "subagent.done"
	// EventFailed is published when a sub-agent fails.
	EventFailed = "subagent.failed"
	// EventAborted is published when a sub-agent is canceled or times out.
	EventAborted = "subagent.aborted"
)

// Progress is the status snapshot carried by a progress event's Data payload.
type Progress struct {
	// AgentID is the spawned sub-agent id.
	AgentID string
	// Goal is the sub-agent's objective.
	Goal string
	// RoleID is the bound role/persona.
	RoleID string
	// Mode is the bound behavior mode.
	Mode string
	// Status is the sub-agent's status at publish time.
	Status Status
}

// Sentinel errors returned by the Scheduler. They are wrapped with %w at call
// sites so callers can test with errors.Is.
var (
	// ErrMissingGoal is returned by Spawn when the spec Goal is blank.
	ErrMissingGoal = errors.New("orchestration: missing goal")

	// ErrNoRunner is returned when a sub-agent runs with no loop runner
	// configured (Options.Loop was nil).
	ErrNoRunner = errors.New("orchestration: no loop runner configured")

	// ErrNoApprover is returned by Approve when no *audit.Approver was injected.
	ErrNoApprover = errors.New("orchestration: no approver configured")

	// ErrNoMemory is returned by SinkMemory when no *memory.Store was injected.
	ErrNoMemory = errors.New("orchestration: no memory store configured")

	// ErrAgentNotFound is returned by Abort when the sub-agent id is unknown.
	ErrAgentNotFound = errors.New("orchestration: sub-agent not found")
)

// cloneMessages returns a deep copy of msgs: the message slice and each message's
// content parts are copied so the result shares no memory with the input. It is
// used at Spawn to give each sub-agent an isolated context. A nil input yields
// nil; a non-nil empty input yields a non-nil empty slice.
func cloneMessages(msgs []model.Message) []model.Message {
	if msgs == nil {
		return nil
	}
	out := make([]model.Message, len(msgs))
	for i, m := range msgs {
		if m.Content != nil {
			parts := make([]model.Content, len(m.Content))
			copy(parts, m.Content)
			m.Content = parts
		}
		out[i] = m
	}
	return out
}

// compactText shortens s to at most n runes for inclusion in a summary, appending
// an ellipsis when it was truncated. It never splits a multi-byte rune.
func compactText(s string, n int) string {
	s = strings.TrimSpace(s)
	r := []rune(s)
	if len(r) <= n {
		return s
	}
	return string(r[:n]) + "…"
}