package repo

import (
	"crypto/sha256"
	"encoding/hex"
	"sort"
	"strings"

	"browser.local/platform/domain"
)

func normalizeStoreSnapshot(snapshot StoreSnapshot) StoreSnapshot {
	plugins, replacements := latestGamePlugins(snapshot.GamePlugins)
	snapshot.GamePlugins = plugins
	snapshot.ServerInstances = rewriteSnapshotServerInstances(snapshot.ServerInstances, replacements)
	snapshot.RuntimeBindings = rewriteSnapshotRuntimeBindings(snapshot.RuntimeBindings, replacements)
	snapshot.PluginLifecycles = rewriteSnapshotPluginLifecycles(snapshot.PluginLifecycles, replacements)
	snapshot.PluginDataRecords = retainedSnapshotPluginData(snapshot.PluginDataRecords, replacements)
	return snapshot
}

func latestGamePlugins(values []domain.GamePlugin) ([]domain.GamePlugin, map[string]domain.GamePlugin) {
	byIdentity := map[string]domain.GamePlugin{}
	for _, plugin := range values {
		key := domain.GamePluginIdentityKey(plugin)
		if current, exists := byIdentity[key]; !exists || domain.GamePluginIsNewer(plugin, current) {
			byIdentity[key] = plugin
		}
	}
	replacements := map[string]domain.GamePlugin{}
	out := make([]domain.GamePlugin, 0, len(byIdentity))
	for _, plugin := range byIdentity {
		out = append(out, domain.CopyGamePlugin(plugin))
	}
	sort.SliceStable(out, func(left, right int) bool { return out[left].ID < out[right].ID })
	for _, plugin := range values {
		kept, ok := byIdentity[domain.GamePluginIdentityKey(plugin)]
		if ok && plugin.ID != kept.ID {
			replacements[plugin.ID] = kept
		}
	}
	return out, replacements
}

func rewriteSnapshotServerInstances(values []domain.ServerInstance, replacements map[string]domain.GamePlugin) []domain.ServerInstance {
	out := make([]domain.ServerInstance, len(values))
	for index, value := range values {
		if kept, ok := replacements[value.PluginID]; ok {
			value.PluginID = kept.ID
			value.PluginVersion = kept.Version
		}
		out[index] = domain.CopyServerInstance(value)
	}
	return out
}

func rewriteSnapshotRuntimeBindings(values []domain.RuntimeBinding, replacements map[string]domain.GamePlugin) []domain.RuntimeBinding {
	out := make([]domain.RuntimeBinding, len(values))
	for index, value := range values {
		if kept, ok := replacements[value.PluginID]; ok {
			value.PluginID = kept.ID
			value.PluginVersion = kept.Version
		}
		out[index] = domain.CopyRuntimeBinding(value)
	}
	return out
}

func rewriteSnapshotPluginLifecycles(values []domain.PluginLifecycleInstallation, replacements map[string]domain.GamePlugin) []domain.PluginLifecycleInstallation {
	out := make([]domain.PluginLifecycleInstallation, len(values))
	for index, value := range values {
		if kept, ok := replacements[value.PluginID]; ok {
			value.PluginID = kept.ID
			if value.TargetVersion != "" {
				value.TargetVersion = kept.Version
			}
		}
		out[index] = domain.CopyPluginLifecycleInstallation(value)
	}
	return out
}

func retainedSnapshotPluginData(values []domain.PluginDataRecord, replacements map[string]domain.GamePlugin) []domain.PluginDataRecord {
	byID := map[string]domain.PluginDataRecord{}
	for _, value := range values {
		if isLegacySCUMPluginData(value.PluginID, value.Collection) {
			continue
		}
		if kept, ok := replacements[value.PluginID]; ok {
			value.PluginID = kept.ID
			value.ID = snapshotPluginDataID(value.ServerInstanceID, kept.ID, value.Collection, value.Key)
		}
		if current, exists := byID[value.ID]; !exists || value.UpdatedAt.After(current.UpdatedAt) || (value.UpdatedAt.Equal(current.UpdatedAt) && value.CreatedAt.After(current.CreatedAt)) {
			byID[value.ID] = domain.CopyPluginDataRecord(value)
		}
	}
	ids := make([]string, 0, len(byID))
	for id := range byID {
		ids = append(ids, id)
	}
	sort.Strings(ids)
	out := make([]domain.PluginDataRecord, 0, len(ids))
	for _, id := range ids {
		out = append(out, domain.CopyPluginDataRecord(byID[id]))
	}
	return out
}

func isLegacySCUMPluginData(pluginID string, collection string) bool {
	if !isSCUMPluginID(pluginID) {
		return false
	}
	switch strings.ToLower(strings.TrimSpace(collection)) {
	case "scum_users", "scum_players", "scum_trajectories", "scum_user_trajectories", "scum_vehicles", "scum_vehicle_trajectories", "scum_vehicle_locks":
		return true
	default:
		return false
	}
}

func isSCUMPluginID(pluginID string) bool {
	canonical := domain.CanonicalGamePluginID(pluginID)
	return canonical == "game.scum" || canonical == "server.scum"
}

func snapshotPluginDataID(serverID, pluginID, collection, key string) string {
	sum := sha256.Sum256([]byte(serverID + "\x00" + pluginID + "\x00" + collection + "\x00" + key))
	return "plugin-data-" + hex.EncodeToString(sum[:])[:24]
}