package pipeline

import (
	"strings"

	"evobgp/internal/store"
)

// moduleIngestInputHash fingerprints module config and child entries so snapshots invalidate on CRUD.
func moduleIngestInputHash(st store.Backend, tenantID string, mod *store.Module) (string, error) {
	return store.ComputeModuleInputHash(st, tenantID, mod)
}

func persistModuleSnapshot(st store.Backend, tenantID string, mod *store.Module, rows []store.PrefixRow) error {
	if st == nil || mod == nil {
		return nil
	}
	hash, err := moduleIngestInputHash(st, tenantID, mod)
	if err != nil {
		return err
	}
	if err := st.SetModulePrefixSnapshot(tenantID, mod.ID, hash, rows); err != nil {
		return err
	}
	_ = st.SetModuleInputHash(tenantID, mod.ID, hash)
	return nil
}

func moduleRowsFromSnapshot(st store.Backend, tenantID string, mod *store.Module) ([]store.PrefixRow, bool, error) {
	snap, ok, err := st.GetModulePrefixSnapshot(tenantID, mod.ID)
	if err != nil || !ok || snap == nil {
		return nil, false, err
	}
	if h := strings.TrimSpace(mod.InputHash); h != "" {
		if snap.InputHash != h {
			return nil, false, nil
		}
		return append([]store.PrefixRow(nil), snap.Prefixes...), true, nil
	}
	// Fallback for rows written before module.input_hash existed: recompute and backfill.
	hash, err := moduleIngestInputHash(st, tenantID, mod)
	if err != nil {
		return nil, false, err
	}
	if snap.InputHash != hash {
		return nil, false, nil
	}
	_ = st.SetModuleInputHash(tenantID, mod.ID, hash)
	return append([]store.PrefixRow(nil), snap.Prefixes...), true, nil
}