package bm

import (
	"context"
	"time"

	"git.golem15.com/golem15/summercms/modules/lighthouse"
	"git.golem15.com/jakub/sm-bm-plugin/classes"
	"git.golem15.com/jakub/sm-bm-plugin/controllers/api"
	"gorm.io/gorm"
)

// registerMaterialsRealtime registers the authorizer of the materials
// namespace: channel materials:{id} carries the live revision heads-up of
// one material (D-20) and is open only to whoever may manage it.
func (p *Plugin) registerMaterialsRealtime(svc *lighthouse.Service) error {
	return svc.Registry().Register(classes.MaterialsNamespace, lighthouse.AuthorizerFunc(p.authorizeMaterial))
}

// authorizeMaterial allows a subscribe to materials:{id} only when the
// material is visible to the user and they may manage it (jz.bm.access_materials
// and its author, or any such user while it has no author). It checks the
// current state on every subscribe. The deny reasons are for the logs.
func (p *Plugin) authorizeMaterial(ctx context.Context, userID uint, channel string) lighthouse.Result {
	id, ok := classes.MaterialChannelID(channel)
	if !ok {
		return lighthouse.Denied("malformed material channel")
	}
	db := p.database()
	if db == nil {
		return lighthouse.Denied("database unavailable")
	}
	allowed, err := p.canWatchMaterial(ctx, db, userID, id)
	if err != nil {
		return lighthouse.Denied("material lookup failed")
	}
	if !allowed {
		return lighthouse.Denied("not the material's manager")
	}
	return lighthouse.Allowed(nil)
}

// canWatchMaterial runs the watchMaterial seam, or api.CanWatchMaterial at
// the current time by default.
func (p *Plugin) canWatchMaterial(ctx context.Context, db *gorm.DB, userID, id uint) (bool, error) {
	if p.watchMaterial != nil {
		return p.watchMaterial(ctx, db, userID, id)
	}
	return api.CanWatchMaterial(ctx, db, time.Now(), userID, id)
}