package app

import (
	"encoding/json"
	"os"
	"path/filepath"
	"time"
)

func loadTransportPolicyState() TransportPolicyState {
	st := TransportPolicyState{Version: transportStateVersion, Revision: 0}
	data, err := os.ReadFile(transportPolicyStatePath)
	if err != nil {
		return st
	}
	if err := json.Unmarshal(data, &st); err != nil {
		return TransportPolicyState{Version: transportStateVersion, Revision: 0}
	}
	if st.Version == 0 {
		st.Version = transportStateVersion
	}
	if st.Intents == nil {
		st.Intents = nil
	}
	return st
}

func saveTransportPolicyState(st TransportPolicyState) error {
	st.Version = transportStateVersion
	st.UpdatedAt = time.Now().UTC().Format(time.RFC3339)

	data, err := json.MarshalIndent(st, "", "  ")
	if err != nil {
		return err
	}
	if err := os.MkdirAll(filepath.Dir(transportPolicyStatePath), 0o755); err != nil {
		return err
	}
	tmp := transportPolicyStatePath + ".tmp"
	if err := os.WriteFile(tmp, data, 0o644); err != nil {
		return err
	}
	return os.Rename(tmp, transportPolicyStatePath)
}

func saveTransportPolicySnapshot(st TransportPolicyState) error {
	data, err := json.MarshalIndent(st, "", "  ")
	if err != nil {
		return err
	}
	if err := os.MkdirAll(filepath.Dir(transportPolicySnapshotPath), 0o755); err != nil {
		return err
	}
	tmp := transportPolicySnapshotPath + ".tmp"
	if err := os.WriteFile(tmp, data, 0o644); err != nil {
		return err
	}
	return os.Rename(tmp, transportPolicySnapshotPath)
}

func loadTransportPolicySnapshot() (TransportPolicyState, bool) {
	data, err := os.ReadFile(transportPolicySnapshotPath)
	if err != nil {
		return TransportPolicyState{}, false
	}
	var st TransportPolicyState
	if err := json.Unmarshal(data, &st); err != nil {
		return TransportPolicyState{}, false
	}
	if st.Version == 0 {
		st.Version = transportStateVersion
	}
	return st, true
}