package sensor

import (
    _"fmt"
    "time"
    "sync"
    _ "FRMS/internal/pkg/I2C"
    "log"
)

type Manager struct {
    *Dev
    I2CDevice
    *Active
    Hb time.Duration
}

type Active struct {
    sync.Mutex
    bool
    int
}

type Dev struct {
    // last known values
    Addr int
    Type string
    Status string // could be more efficient but to hell with it
}

type I2CDevice interface {
    // basic device info
    GetAddr() int
    GetStatus() string
    GetType() string
}

func NewDeviceManager(i2c I2CDevice) *Manager  {
    m := &Manager{Hb:time.Duration(1*time.Second)}
    m.I2CDevice = i2c
    m.Active = &Active{}
    m.Dev = &Dev{Addr:i2c.GetAddr(),Type:i2c.GetType(),Status:i2c.GetStatus()}
    return m
}

func (m *Manager) Start() {
    // goal is to start a long running monitoring routine
    if !m.Activate() {
        log.Fatal("Manager already running!")
    } // atomically activated if this runs
    go m.Monitor()
}

func (m *Manager) Exit() {
    if !m.Deactivate() {
        log.Fatal("Manager already exited!")
    }
}

func (m *Manager) Monitor() {
    for m.IsActive() {
        if m.Status == "KILLED" {
            m.Exit()
        }
        time.Sleep(m.Hb)
    }
}

func (m *Manager) GetType() string {
    return m.Type
}

func (m *Manager) GetStatus() string {
    m.Status = m.I2CDevice.GetStatus()
    return m.Status
}

func (m *Manager) GetData() string {
    return ""
}

func (m *Manager) GetAddr() int {
    return m.Addr
}

// atomic activation and deactivation
func (a *Active) Activate() bool {
    // returns true if success, false otherwise
    a.Lock()
    defer a.Unlock()
    if a.bool {         // already active
        return false
    } else {
        a.bool = true
        a.int = 0
        return a.bool
    }
}

func (a *Active) Deactivate() bool {
    // returns true if success false otherise
    a.Lock()
    defer a.Unlock()
    if a.bool {
        a.bool = false
        return true
    } else {            // already deactivated
        return a.bool   // false
    }
}

func (a *Active) IsActive() bool {
    a.Lock()
    defer a.Unlock()
    return a.bool
}