package controllers

import (
	"sync"
	"time"

	"github.com/rs/zerolog/log"
)

type ChamberState int

const (
	ChamberStateIdle ChamberState = iota
	ChamberStateCooling
	ChamberStateHeating
)

type ChamberController struct {
	config *Config

	// Current state.
	chamberState           ChamberState
	lastChamberStateChange time.Time
	C                      chan ChamberState
	mutex                  *sync.Mutex

	name string

	// Current temperature readings.
	ambientTemperature float64
	chamberTemperature float64
	wortTemperature    float64

	pid         *PIDController
	initialized bool
}

func NewChamberController(name string, config *Config) *ChamberController {
	return &ChamberController{
		C:      make(chan ChamberState),
		name:   name,
		config: config,
		pid:    NewPIDController(config.PID.Kp, config.PID.Ki, config.PID.Kd),
		mutex:  &sync.Mutex{},
	}
}

func (p *ChamberController) Run() {
	for {
		offset := p.pid.Compute(p.wortTemperature, p.config.FermentationTemperature)
		chamberTargetTemp := p.config.FermentationTemperature + offset
		log.Debug().Float64("chamber_target_temp", chamberTargetTemp).Send()

		// TODO Merge hysteresis algorithm into this one.

		if !p.initialized {
			// heater off
			// cooler off
			continue
		}

		if p.wortTemperature < p.config.FermentationTemperature && p.chamberTemperature < chamberTargetTemp {
			// heater on
		} else if p.wortTemperature >= p.config.FermentationTemperature || p.chamberTemperature >= chamberTargetTemp {
			// heater off
		} else {
			// heater off
		}

		if p.wortTemperature > p.config.FermentationTemperature && p.chamberTemperature > chamberTargetTemp {
			// cooler on
		} else if p.wortTemperature <= p.config.FermentationTemperature || p.chamberTemperature <= chamberTargetTemp {
			// cooler off
		} else {
			// cooler off
		}
	}
}