package coordinator

import (
	"context"
	"log/slog"
	"time"

	"chat-agent-system/internal/jevdecide"
)

// DecideAssist is the narrow port for typed jev decisions (nil-safe).
// Implemented by *jevdecide.Client; injected from the app composition root.
type DecideAssist interface {
	DecideRealtime(ctx context.Context, userInput string) (yes bool, ans jevdecide.Answer, err error)
	DecideProfileBucket(ctx context.Context, userInput string) (bucket string, ans jevdecide.Answer, err error)
}

// SetDecideAssist injects the optional jev decide client; nil disables product integration.
func (e *CoordinatorEngine) SetDecideAssist(d DecideAssist) {
	if e != nil {
		e.decideAssist = d
	}
}

// resolveRealtimeQuery applies rule + optional jev shadow/assist.
// Rules always run. In assist mode, high-confidence jev "yes" can only ADD recall
// (rule || jevYes); it never turns a rule-true into false.
func (e *CoordinatorEngine) resolveRealtimeQuery(ctx context.Context, userInput string) bool {
	rule := IsRealtimeInformationQuery(userInput)
	mode := jevdecide.CurrentMode()
	if mode == jevdecide.ModeOff || e == nil || e.decideAssist == nil {
		return rule
	}
	yes, ans, err := e.decideAssist.DecideRealtime(ctx, userInput)
	if err != nil {
		jevdecide.Global.JevFail.Add(1)
		slog.Info("jevdecide realtime fail-open", "err", err.Error(), "rule", rule)
		return rule
	}
	agree := yes == rule
	if agree {
		jevdecide.Global.Agree.Add(1)
	} else {
		jevdecide.Global.Disagree.Add(1)
	}
	slog.Info("jevdecide realtime shadow",
		"mode", string(mode), "rule", rule, "jev", yes,
		"confidence", ans.Confidence, "margin", ans.Margin(), "agree", agree)

	if mode != jevdecide.ModeAssist {
		return rule
	}
	// assist: conservative synthesis — rules are the floor
	if yes && ans.Reliable(jevdecide.MinAssistConf, jevdecide.MinAssistMargin) {
		if !rule {
			jevdecide.Global.AssistHit.Add(1)
		}
		return true
	}
	return rule
}

// shadowProfile observes jev complexity bucket without changing routing.
func (e *CoordinatorEngine) shadowProfile(ctx context.Context, userInput string, profile TaskProfile) {
	mode := jevdecide.CurrentMode()
	if mode == jevdecide.ModeOff || e == nil || e.decideAssist == nil {
		return
	}
	start := time.Now()
	bucket, ans, err := e.decideAssist.DecideProfileBucket(ctx, userInput)
	_ = start
	ruleBucket := jevdecide.ProfileBucket(profile.ComplexityScore)
	if err != nil {
		jevdecide.Global.JevFail.Add(1)
		slog.Info("jevdecide profile fail-open", "err", err.Error(), "rule_bucket", ruleBucket)
		return
	}
	agree := bucket == ruleBucket
	if agree {
		jevdecide.Global.Agree.Add(1)
	} else {
		jevdecide.Global.Disagree.Add(1)
	}
	slog.Info("jevdecide profile shadow",
		"mode", string(mode), "rule_bucket", ruleBucket, "jev_bucket", bucket,
		"score", profile.ComplexityScore, "confidence", ans.Confidence, "agree", agree)
}