package docnotify

import (
	"context"
	"encoding/json"

	"chat-agent-system/internal/ctxmgr"
	"chat-agent-system/internal/docgov"
	"chat-agent-system/internal/events"
	"chat-agent-system/internal/notification"

	"github.com/jackc/pgx/v5"
)

// EventConsumer is the durable notify worker. Closures remain the unique writer until live cutover.
type EventConsumer struct {
	Notify *notification.Service
	Docs   DocumentLookup
	Chat   *ctxmgr.ContextManager
	Env    string
}

func (c *EventConsumer) HandleLease(ctx context.Context, lease events.Lease, tx pgx.Tx) error {
	if c == nil || c.Notify == nil {
		return events.ErrUnknownConsumer
	}
	principal := events.ServicePrincipal{
		ID: "notify-" + c.Env, Environment: c.Env, Consumer: events.ConsumerNotify,
		Actions: []string{"notify.emit"},
	}
	if err := events.AuthorizePrincipal(principal, lease.Environment, lease.ProjectID, "notify.emit"); err != nil {
		return events.ErrQuarantine
	}
	kind, title, body := notifyCopy(lease.EventName)
	if kind == "" {
		return nil
	}
	docID := lease.Envelope.AggregateID
	var payload map[string]any
	_ = json.Unmarshal(lease.Envelope.Payload, &payload)
	if payload != nil {
		if id, ok := payload["doc_id"].(string); ok && id != "" {
			docID = id
		}
	}
	var recipient int64
	projectID := lease.ProjectID
	var doc *docgov.DocumentRecord
	if c.Docs != nil && docID != "" {
		d, err := c.Docs.GetDocument(ctx, docID)
		if err != nil || d == nil {
			return events.ErrQuarantine
		}
		if d.ProjectID != lease.ProjectID {
			return events.ErrQuarantine
		}
		doc = d
		projectID = d.ProjectID
	}
	recipient = RecipientForDocEvent(doc, lease.EventName)
	if recipient <= 0 && doc != nil {
		recipient = doc.AuthorID
	}
	if recipient <= 0 {
		return events.ErrQuarantine
	}
	p := notification.DocumentEventPayload{ProjectID: projectID, DocID: docID}
	if err := c.Notify.EmitVisibleDocumentEvent(ctx, tx, lease.EventID, kind, title, body, recipient, p); err != nil {
		return err
	}
	if lease.EventName == events.EventDownstreamImpact && c.Chat != nil {
		impacted, _ := payload["impacted_doc_id"].(string)
		_ = PostProjectNotice(ctx, c.Chat, projectID, recipient, downstreamChatBody(docID, impacted), nil)
	}
	return nil
}

func IntendedNotifyDigest(eventID, kind string, recipient int64) string {
	return events.VisibleOutcomeDigest(eventID, kind, recipient)
}

func notifyCopy(eventName string) (kind, title, body string) {
	switch eventName {
	case events.EventCandidateReady:
		return notification.TypeDocAgentCandidateReady, "智能体变更待确认", "文档有高风险智能体候选变更，请确认后生效。"
	case events.EventVersionCommitted:
		return notification.TypeDocAgentVersionCommitted, "智能体版本已生效", "新的智能体文档版本已提交。"
	case events.EventDownstreamImpact:
		return notification.TypeDocDownstreamImpact, "下游文档受影响", "上游文档变更，请复核关联文档。"
	case events.EventChangeReportDegraded:
		return notification.TypeDocChangeReportDegraded, "变更报告未完整评估", "变更报告降级，受控文档暂不可送审。"
	case events.EventApproved:
		return notification.TypeDocApproved, "文档已批准", "文档已完成终审批准。"
	case events.EventDocProposalRequired:
		return notification.TypeDocProposalRequired, "文档变更待确认", "已认领文档有变更提案，请确认后由您发起修改。"
	case events.EventDocUnclaimedEdit:
		return notification.TypeDocUnclaimedEditApplied, "文档已更新", "未认领文档已被直接更新（无需您确认）。"
	case notification.EventDocReviewRequested:
		return notification.TypeDocReviewRequested, "文档待审核", "有文档已送审，请审核。"
	case notification.EventDocApprovalRequested:
		return notification.TypeDocApprovalRequested, "文档待批准", "审核已通过，请批准。"
	case notification.EventDocRejected:
		return notification.TypeDocRejected, "文档已驳回", "文档已被驳回，请查看原因并修订。"
	case notification.EventDocReopened:
		return notification.TypeDocReopened, "文档已重开", "文档已重开修订，请继续编制。"
	default:
		return "", "", ""
	}
}