package mt12232a

import (
	"fmt"
	"io"
	"log"
	"time"

	"gitea.unprism.ru/yotia/display-test/pkg/parallel8bit"
	"github.com/stianeikeland/go-rpio/v4"
)

type mt12232a struct {
	logger *log.Logger

	dev parallel8bit.Device

	pinCS  rpio.Pin
	pinRES rpio.Pin
}

type Device interface {
	PowerOn() error

	WriteCodeL(c byte) error
	WriteCodeR(c byte) error
	WriteDataL(b byte) error
	WriteDataR(b byte) error
	WriteDatasL(b []byte) error
	WriteDatasR(b []byte) error

	ReadDataL() (byte, error)
	ReadDataR() (byte, error)
	ReadStatus(cs rpio.State) byte

	io.Closer
}

func New(logger *log.Logger) (Device, error) {
	rpio.Open()

	d := mt12232a{
		logger: logger,

		dev: parallel8bit.New(logger, parallel8bit.DevicePins{
			PinA0: rpio.Pin(19),
			PinRW: rpio.Pin(13),
			PinE:  rpio.Pin(12),

			PinDB0: rpio.Pin(22),
			PinDB1: rpio.Pin(10),
			PinDB2: rpio.Pin(9),
			PinDB3: rpio.Pin(11),
			PinDB4: rpio.Pin(21),
			PinDB5: rpio.Pin(20),
			PinDB6: rpio.Pin(26),
			PinDB7: rpio.Pin(16),
		}),

		pinCS:  rpio.Pin(17),
		pinRES: rpio.Pin(27),
	}
	d.pinCS.Output()
	d.pinRES.Output()
	d.dev.Reset()

	return &d, nil
}

func (d *mt12232a) Close() error {
	return rpio.Close()
}

func (d *mt12232a) status() {
	d.logger.Println("STATUS:", d.ReadStatus(0)&0xF0, d.ReadStatus(1)&0xF0)
}

func (d *mt12232a) PowerOn() error {
	d.status()
	d.logger.Println(d.ReadStatus(0)) // Should be 0
	d.logger.Println("Reset")
	d.status()
	d.pinRES.Low()
	time.Sleep(time.Microsecond)
	d.logger.Println(d.ReadStatus(0)) // Should be 48 (power off and reset)
	d.pinRES.High()
	time.Sleep(4 * time.Millisecond)
	d.logger.Println(d.ReadStatus(0)) // Should be 32 (power off)

	// Module is reset and should be turned off
	if d.ReadStatus(0) == 0 || d.ReadStatus(1) == 0 {
		return fmt.Errorf("no response from display(or it is possible that it is turned on but...)")
	}
	for i := 0; i < 100; i++ {
		if ((d.ReadStatus(0) >> 4) & 1) == 0 {
			break
		}
	}
	d.status()
	d.status()
	d.status()

	d.logger.Println("Power on")
	d.status()
	d.WriteCodeL(0xE2) // Reset
	d.WriteCodeR(0xE2) // Reset
	d.WriteCodeL(0xEE) // ReadModifyWrite off
	d.WriteCodeR(0xEE) // ReadModifyWrite off
	d.WriteCodeL(0xA4) // Turn on common mode
	d.WriteCodeR(0xA4) // Turn on common mode
	d.WriteCodeL(0xA9) // Multiplex 1/32
	d.WriteCodeR(0xA9) // Multiplex 1/32
	d.WriteCodeL(0xC0) // Top line to 0
	d.WriteCodeR(0xC0) // Top line to 0
	d.WriteCodeL(0xA1) // Invert scan RAM
	d.WriteCodeR(0xA0) // NonInvert scan RAM

	d.status()
	d.logger.Println("Display on")
	d.WriteCodeL(0xAF) // Display on
	d.WriteCodeR(0xAF) // Display on

	d.status()
	time.Sleep(100 * time.Millisecond)
	d.status()
	time.Sleep(100 * time.Millisecond)
	d.status()
	time.Sleep(100 * time.Millisecond)
	d.status()
	time.Sleep(100 * time.Millisecond)
	d.status()
	time.Sleep(100 * time.Millisecond)
	d.status()
	time.Sleep(100 * time.Millisecond)
	d.status()
	time.Sleep(100 * time.Millisecond)
	d.status()
	time.Sleep(100 * time.Millisecond)
	d.status()
	time.Sleep(100 * time.Millisecond)
	d.status()
	time.Sleep(100 * time.Millisecond)

	// Check that crystals are turned on
	if ((d.ReadStatus(0) >> 5) & 1) == 1 {
		d.logger.Println("Left cristal is still off")
	}
	if ((d.ReadStatus(0) >> 5) & 1) == 1 {
		d.logger.Println("Right cristal is still off")
	}

	// The same but with error
	if ((d.ReadStatus(0) >> 5) & 1) == 1 {
		return fmt.Errorf("Left cristal is still off")
	}
	if ((d.ReadStatus(0) >> 5) & 1) == 1 {
		return fmt.Errorf("Right cristal is still off")
	}

	return nil
}

// Write codes

func (d *mt12232a) WriteCodeL(c byte) error {
	return d.writeByte(c, 0, 0)
}

func (d *mt12232a) WriteCodeR(c byte) error {
	return d.writeByte(c, 0, 1)
}

// Write data as byte

func (d *mt12232a) WriteDataL(b byte) error {
	return d.writeByte(b, 1, 0)
}

func (d *mt12232a) WriteDataR(b byte) error {
	return d.writeByte(b, 1, 1)
}

func (d *mt12232a) WriteDatasL(b []byte) error {
	return d.writeBytes(b, 1, 0)
}

func (d *mt12232a) WriteDatasR(b []byte) error {
	return d.writeBytes(b, 1, 1)
}

// Read data

func (d *mt12232a) ReadDataL() (byte, error) {
	return d.readByte(1, 0)
}

func (d *mt12232a) ReadDataR() (byte, error) {
	return d.readByte(1, 1)
}

// Low level functions

func (d *mt12232a) writeByte(b byte, cd, cs rpio.State) error {
	if err := d.waitReady(cs); err != nil {
		return fmt.Errorf("wait ready: %w", err)
	}
	d.pinCS.Write(cs) // Select cristals

	d.dev.WriteByte(b, cd)
	return nil
}

func (d *mt12232a) writeBytes(b []byte, cd, cs rpio.State) error {
	if err := d.waitReady(cs); err != nil {
		return fmt.Errorf("wait ready: %w", err)
	}
	d.pinCS.Write(cs) // Select cristals

	d.dev.WriteBytes(b, cd)
	return nil
}

func (d *mt12232a) readByte(cd, cs rpio.State) (byte, error) {
	// Setup
	if err := d.waitReady(cs); err != nil {
		return 0, fmt.Errorf("wait ready: %w", err)
	}
	d.pinCS.Write(cs) // Select cristals

	return d.dev.ReadByte(cd), nil
}

// Wait, checking status byte
func (d *mt12232a) waitReady(cs rpio.State) error {
	d.pinCS.Write(cs) // Select cristals
	return d.dev.WaitReady()
}

func (d *mt12232a) ReadStatus(cs rpio.State) byte {
	d.pinCS.Write(cs) // Select cristals
	return d.dev.ReadByte(1)
}