package cabana

import (
	"context"

	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/lagoon"
	"git.golem15.com/golem15/summercms/modules/pact"

	"gorm.io/gorm"
)

// backendSubjectGuard is the guard name backend subject events carry: the
// admin's own bouncer guard.
const backendSubjectGuard = "backend"

// fireSubjectChanged fires one pact.MCPSubjectChanged of the given kind for
// every administrator id through the application's event bus, so the MCP
// endpoint re-lists a linked admin's tools or ends their sessions. The event
// is a *pact.MCPSubjectChanged, the type pier listens for. Inside a
// transaction it fires only after the commit, so a rolled-back save fires
// nothing; outside one it fires at once. A missing application or bus is a
// no-op and a listener's error is logged: the save that caused the event
// never fails because of it.
func fireSubjectChanged(ctx context.Context, app *backpack.App, kind string, adminIDs ...uint) {
	if app == nil || app.Events == nil {
		return
	}
	if ctx == nil {
		ctx = context.Background()
	}
	tx, _ := TxFromContext(ctx)
	lagoon.AfterCommit(ctx, tx, func(ctx context.Context, _ *gorm.DB) {
		for _, id := range adminIDs {
			if id == 0 {
				continue
			}
			event := &pact.MCPSubjectChanged{Guard: backendSubjectGuard, UserID: id, Kind: kind}
			if err := app.Events.Fire(ctx, event); err != nil {
				moduleLog.WarnContext(ctx, "cabana: subject changed listener failed", "kind", kind, "admin_id", id, "error", err)
			}
		}
	})
}

// fireTokenRevoked fires one pact.MCPSubjectRevoked for an administrator's
// personal token, narrowed to that token with TokenID: the MCP endpoint ends
// only the sessions opened with this token, not the admin's other sessions
// (another token, or an OAuth grant acting as the linked admin). It fires
// after the commit like fireSubjectChanged and never fails the revoke.
func fireTokenRevoked(ctx context.Context, app *backpack.App, adminID, tokenID uint) {
	if app == nil || app.Events == nil || adminID == 0 || tokenID == 0 {
		return
	}
	if ctx == nil {
		ctx = context.Background()
	}
	tx, _ := TxFromContext(ctx)
	lagoon.AfterCommit(ctx, tx, func(ctx context.Context, _ *gorm.DB) {
		event := &pact.MCPSubjectChanged{Guard: backendSubjectGuard, UserID: adminID, Kind: pact.MCPSubjectRevoked, TokenID: tokenID}
		if err := app.Events.Fire(ctx, event); err != nil {
			moduleLog.WarnContext(ctx, "cabana: subject changed listener failed", "kind", pact.MCPSubjectRevoked, "admin_id", adminID, "token_id", tokenID, "error", err)
		}
	})
}