package appcontext

import (
	"fmt"
	"log/slog"
	"os"
	"time"

	"github.com/AFASystems/presence/internal/pkg/kafkaclient"
	"github.com/mitchellh/mapstructure"
)

// AppState provides centralized access to application state
type AppState struct {
	beacons       BeaconsList
	settings      Settings
	beaconEvents  BeaconEventList
	beaconsLookup BeaconsLookup
	health        Health
	startTime     time.Time
}

func getEnv(key, def string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return def
}

// NewAppState creates a new application context AppState with default values
func NewAppState() *AppState {
	return &AppState{
		startTime: time.Now(),
		beacons: BeaconsList{
			Beacons: make(map[string]Beacon),
		},
		settings: Settings{
			ID:                   1,
			CurrentAlgorithm:     getEnv("ALGORITHM", "filter"),
			LocationConfidence:   4,
			LastSeenThreshold:    15,
			BeaconMetricSize:     30,
			HASendInterval:       5,
			HASendChangesOnly:    false,
			RSSIEnforceThreshold: false,
			RSSIMinThreshold:     100,
		},
		beaconEvents: BeaconEventList{
			Beacons: make(map[string]BeaconEvent),
		},
		beaconsLookup: BeaconsLookup{
			Lookup: make(map[string]string),
		},
		health: Health{
			ID: "1",
			Location: LocationHealth{
				BaseHealth: BaseHealth{
					Uptime:        0,
					ActiveReaders: []string{},
					ActiveWriters: []string{},
					ActiveBeacons: []string{},
				},
			},
			Decoder: DecoderHealth{
				BaseHealth: BaseHealth{
					Uptime:        0,
					ActiveReaders: []string{},
					ActiveWriters: []string{},
					ActiveBeacons: []string{},
				},
			},
			Bridge: BridgeHealth{
				BaseHealth: BaseHealth{
					Uptime:        0,
					ActiveReaders: []string{},
					ActiveWriters: []string{},
					ActiveBeacons: []string{},
				},
			},
		},
	}
}

func (m *AppState) GetLocationHealth(k *kafkaclient.KafkaManager) ([]byte, error) {
	m.health.Location.GetUptime(m.startTime)
	m.health.Location.GetActiveReaders(k)
	m.health.Location.GetActiveWriters(k)
	m.health.Location.GetActiveBeacons(m)
	return m.health.Location.Marshal()
}

func (m *AppState) GetDecoderHealth(k *kafkaclient.KafkaManager) ([]byte, error) {
	m.health.Decoder.GetUptime(m.startTime)
	m.health.Decoder.GetActiveReaders(k)
	m.health.Decoder.GetActiveWriters(k)
	m.health.Decoder.GetActiveBeacons(m)
	return m.health.Decoder.Marshal()
}

func (m *AppState) GetBridgeHealth(k *kafkaclient.KafkaManager) ([]byte, error) {
	m.health.Bridge.GetUptime(m.startTime)
	m.health.Bridge.GetActiveReaders(k)
	m.health.Bridge.GetActiveWriters(k)
	m.health.Bridge.GetActiveBeacons(m)
	return m.health.Bridge.Marshal()
}

// GetBeacons returns thread-safe access to beacons list
func (m *AppState) GetBeacons() *BeaconsList {
	m.beacons.Lock.RLock()
	defer m.beacons.Lock.RUnlock()
	return &m.beacons
}

// GetSettings returns thread-safe access to settings
func (m *AppState) GetSettings() *Settings {
	return &m.settings
}

// GetBeaconEvents returns thread-safe access to beacon events
func (m *AppState) GetBeaconEvents() *BeaconEventList {
	m.beaconEvents.Lock.RLock()
	defer m.beaconEvents.Lock.RUnlock()
	return &m.beaconEvents
}

// AddBeaconToLookup adds a beacon ID to the lookup map
func (m *AppState) AddBeaconToLookup(id, value string) {
	m.beaconsLookup.Lock.Lock()
	m.beaconsLookup.Lookup[id] = value
	m.beaconsLookup.Lock.Unlock()
}

// RemoveBeaconFromLookup removes a beacon ID from the lookup map
func (m *AppState) RemoveBeaconFromLookup(id string) {
	m.beaconsLookup.Lock.Lock()
	delete(m.beaconsLookup.Lookup, id)
	m.beaconsLookup.Lock.Unlock()
}

func (m *AppState) CleanLookup() {
	m.beaconsLookup.Lock.Lock()
	clear(m.beaconsLookup.Lookup)
	m.beaconsLookup.Lock.Unlock()
}

// BeaconExists checks if a beacon exists in the lookup
func (m *AppState) BeaconExists(id string) (string, bool) {
	m.beaconsLookup.Lock.RLock()
	defer m.beaconsLookup.Lock.RUnlock()
	val, exists := m.beaconsLookup.Lookup[id]
	return val, exists
}

// GetBeacon returns a beacon by ID (thread-safe)
func (m *AppState) GetBeacon(id string) (Beacon, bool) {
	m.beacons.Lock.RLock()
	defer m.beacons.Lock.RUnlock()

	beacon, exists := m.beacons.Beacons[id]
	return beacon, exists
}

// UpdateBeacon updates a beacon in the list (thread-safe)
func (m *AppState) UpdateBeacon(id string, beacon Beacon) {
	m.beacons.Lock.Lock()
	defer m.beacons.Lock.Unlock()

	m.beacons.Beacons[id] = beacon
}

// GetBeaconEvent returns a beacon event by ID (thread-safe)
func (m *AppState) GetBeaconEvent(id string) (BeaconEvent, bool) {
	m.beaconEvents.Lock.RLock()
	defer m.beaconEvents.Lock.RUnlock()

	event, exists := m.beaconEvents.Beacons[id]
	return event, exists
}

// UpdateBeaconEvent updates a beacon event in the list (thread-safe)
func (m *AppState) UpdateBeaconEvent(id string, event BeaconEvent) {
	m.beaconEvents.Lock.Lock()
	defer m.beaconEvents.Lock.Unlock()

	m.beaconEvents.Beacons[id] = event
}

// GetAllBeacons returns a copy of all beacons
func (m *AppState) GetAllBeacons() map[string]Beacon {
	m.beacons.Lock.RLock()
	defer m.beacons.Lock.RUnlock()

	beacons := make(map[string]Beacon)
	for id, beacon := range m.beacons.Beacons {
		beacons[id] = beacon
	}
	return beacons
}

// GetBeaconCount returns the number of tracked beacons
func (m *AppState) GetBeaconCount() int {
	m.beacons.Lock.RLock()
	defer m.beacons.Lock.RUnlock()

	return len(m.beacons.Beacons)
}

// GetSettingsValue returns current settings as a value
func (m *AppState) GetSettingsValue() Settings {
	return m.settings
}

// UpdateSettings updates the system settings (thread-safe)
func (m *AppState) UpdateSettings(settings map[string]any) {
	if err := mapstructure.Decode(settings, &m.settings); err != nil {
		msg := fmt.Sprintf("Error in persisting settings: %v", err)
		slog.Error(msg)
	}
}