use core::u16;
use crate::thermostat::ad5680;
use fugit::KilohertzU32;
use stm32f4xx_hal::{
    adc::{
        config::{self, AdcConfig},
        Adc,
    },
    gpio::{gpioa::*, gpiob::*, gpioc::*, Alternate, Analog, Output, PushPull},
    hal::{self, blocking::spi::Transfer, digital::v2::OutputPin},
    pac::{ADC1, SPI1, TIM4},
    spi::{NoMiso, Spi, TransferModeNormal},
    timer::pwm::PwmChannel,
};

use uom::si::{
    electric_potential::millivolt,
    f64::ElectricPotential,
    ratio::ratio,
};

pub const PWM_FREQ_KHZ: KilohertzU32 = KilohertzU32::from_raw(20);

pub trait ChannelPins {
    type DacSpi: Transfer<u8>;
    type DacSync: OutputPin;
    type ShdnPin: OutputPin;
    type VRefPin;
    type ItecPin;
    type DacFeedbackPin;
    type VTecPin;
    type MaxVPin;
    type MaxIPosPin;
    type MAXINegPin;
}

pub struct Channel0;

impl ChannelPins for Channel0 {
    type DacSpi = DacSpi;
    type DacSync = DacSync;
    type ShdnPin = PA5<Output<PushPull>>;
    type VRefPin = PA6<Analog>;
    type ItecPin = PB1<Analog>;
    type DacFeedbackPin = PC0<Analog>;
    type VTecPin = PB0<Analog>;
    type MaxVPin = PwmChannel<TIM4, 1>;
    type MaxIPosPin = PwmChannel<TIM4, 2>;
    type MAXINegPin = PwmChannel<TIM4, 0>;
}

pub struct MAX1968Phy<C: ChannelPins> {
    pub dac: ad5680::Dac<C::DacSpi, C::DacSync>,
    pub shdn: C::ShdnPin,
    pub vref_pin: C::VRefPin,
    pub itec_pin: C::ItecPin,
    pub dac_feedback_pin: C::DacFeedbackPin,
    pub vtec_pin: C::VTecPin,
    pub max_v: C::MaxVPin,
    pub max_i_pos: C::MaxIPosPin,
    pub max_i_neg: C::MAXINegPin,
}

pub struct MAX1968PinSet<C: ChannelPins> {
    pub dac: ad5680::Dac<C::DacSpi, C::DacSync>,
    pub shdn: C::ShdnPin,
    pub vref_pin: C::VRefPin,
    pub itec_pin: C::ItecPin,
    pub dac_feedback_pin: C::DacFeedbackPin,
    pub vtec_pin: C::VTecPin,
    pub max_v: C::MaxVPin,
    pub max_i_pos: C::MaxIPosPin,
    pub max_i_neg: C::MAXINegPin,
}

type DacSpi = Spi<SPI1, (PB3<Alternate<5>>, NoMiso, PB5<Alternate<5>>), TransferModeNormal>;
type DacSync = PB4<Output<PushPull>>;

pub struct MAX1968 {
    // settings
    pub phy: MAX1968Phy<Channel0>,
    pub pins_adc: Adc<ADC1>,
}

pub enum PwmPinsEnum {
    MaxV,
    MaxPosI,
    MaxNegI,
}

pub enum AdcReadTarget {
    VREF,
    DacVfb,
    ITec,
    VTec,
}

impl<C: ChannelPins> MAX1968Phy<C> {
    pub fn new(pins: MAX1968PinSet<C>) -> Self {
        MAX1968Phy {
            dac: pins.dac,
            shdn: pins.shdn,
            vref_pin: pins.vref_pin,
            itec_pin: pins.itec_pin,
            dac_feedback_pin: pins.dac_feedback_pin,
            vtec_pin: pins.vtec_pin,
            max_v: pins.max_v,
            max_i_pos: pins.max_i_pos,
            max_i_neg: pins.max_i_neg,
        }
    }
}

impl MAX1968 {
    pub fn new(phy_ch0: MAX1968Phy<Channel0>, adc1: ADC1) -> Self {
        let config = AdcConfig::default()
            .clock(config::Clock::Pclk2_div_8)
            .default_sample_time(config::SampleTime::Cycles_480);
        // Do not set reset RCCs as it causes other ADCs' clock to be disabled
        let mut pins_adc = Adc::adc1(adc1, false, config);
        pins_adc.calibrate();

        MAX1968 {
            phy: phy_ch0,
            pins_adc: pins_adc,
        }
    }

    // Return the calibrated VDDA Voltage
    // Can be used to set reference voltage for other ADC
    pub fn get_calibrated_vdda(&mut self) -> u32 {
        self.pins_adc.reference_voltage()
    }

    pub fn power_down(&mut self) {
        self.phy.shdn.set_low();
    }

    pub fn power_up(&mut self) {
        self.phy.shdn.set_high();
    }


    pub fn set_dac(&mut self, voltage: ElectricPotential, dac_out_v_max: ElectricPotential) -> ElectricPotential {
        let value = ((voltage / dac_out_v_max).get::<ratio>()
            * (ad5680::MAX_VALUE as f64)) as u32;
        self.phy.dac.set(value).unwrap();
        // TODO: Store the set-ed DAC Voltage Value
        voltage
    }

    // AN4073: ADC Reading Dispersion can be reduced through Averaging
    // Upon test, 16 Point Averaging = +-3 LSB Dispersion
    pub fn adc_read(&mut self, adc_read_target: AdcReadTarget, avg_pt: u16) -> ElectricPotential {
        let mut sample: u32 = 0;
        sample = match adc_read_target {
            AdcReadTarget::VREF => {
                for _ in (0..avg_pt).rev() {
                    sample += self.pins_adc.convert(
                        &self.phy.vref_pin,
                        stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
                    ) as u32;
                }
                sample / avg_pt as u32
            }
            AdcReadTarget::DacVfb => {
                for _ in (0..avg_pt).rev() {
                    sample += self.pins_adc.convert(
                        &self.phy.dac_feedback_pin,
                        stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
                    ) as u32;
                }
                sample / avg_pt as u32
            }
            AdcReadTarget::ITec => {
                for _ in (0..avg_pt).rev() {
                    sample += self.pins_adc.convert(
                        &self.phy.itec_pin,
                        stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
                    ) as u32;
                }
                sample / avg_pt as u32
            }
            AdcReadTarget::VTec => {
                for _ in (0..avg_pt).rev() {
                    sample += self.pins_adc.convert(
                        &self.phy.vtec_pin,
                        stm32f4xx_hal::adc::config::SampleTime::Cycles_480,
                    ) as u32;
                }
                sample / avg_pt as u32
            }
        };
        let mv = self.pins_adc.sample_to_millivolts(sample as u16);
        ElectricPotential::new::<millivolt>(mv as f64)
    }

    pub fn set_pwm(&mut self, pwm_pin: PwmPinsEnum, duty: f64, max_duty: f64) -> f64 {
        fn set<P: hal::PwmPin<Duty = u16>>(pin: &mut P, duty: f64) -> f64 {
            let max = pin.get_max_duty();
            let value = ((duty * (max as f64)) as u16).min(max);
            pin.set_duty(value);
            pin.enable();
            value as f64 / (max as f64)
        }

        let duty = duty.min(max_duty);

        match pwm_pin {
            PwmPinsEnum::MaxV => set(&mut self.phy.max_v, duty),
            PwmPinsEnum::MaxPosI => set(&mut self.phy.max_i_pos, duty),
            PwmPinsEnum::MaxNegI => set(&mut self.phy.max_i_neg, duty),
        }
    }

}