package i2c

// file has general wrappers to interact with i2c-tools

import (
	"FRMS/internal/pkg/logging"
	"bytes"
	"fmt"
	_ "log"
	"os/exec"
	"strconv"
	"strings"
)

func GetConnected(b int) (map[int]bool, error) {
	// Returns all the connected devices by address
	// might just do this in bash and make it easier
	bus := strconv.Itoa(b)
	devices := make(map[int]bool) // only keys
	cmd := exec.Command("i2cdetect", "-y", "-r", bus)
	var out bytes.Buffer
	var errs bytes.Buffer
	cmd.Stderr = &errs
	cmd.Stdout = &out
	if err := cmd.Run(); err != nil {
		logging.Debug(logging.DError, "I2C error performing scan. %v", errs.String())
		return devices, err
	}

	outString := out.String()
	// could split by \n too
	split := strings.SplitAfter(outString, ":")
	// 1st entry is garbage headers and ending is always \n##:
	split = split[1:]
	// create empty slice for all the devices
	for i, v := range split {
		lst := strings.Index(v, "\n")
		trimmed := v[:lst]
		trimmed = strings.Trim(trimmed, " ")
		// trimmed now holds just possible sensor addresses
		count := strings.Split(trimmed, " ")
		for j, d := range count {
			// the first row has to be offset by 3 but after its just i*16 + j
			offset := 0
			if i == 0 {
				offset = 3
			}
			addr := i*16 + j + offset
			if !strings.Contains(d, "--") && !strings.Contains(d, "UU") {
				// active
				devices[addr] = true
			}
		}
	}
	return devices, nil
}

func SendCmd(b, addr int, command string) (string, error) {
	// sends an arbituary commnd over specified bus to int
	// might make a base script for this too
	var cmd *exec.Cmd
	bus := strconv.Itoa(b)
	operation := "r20" // default read
	frmt_cmd := ""     // empty cmd
	if command != "" {
		// command, do write
		operation = fmt.Sprintf("w%d", len(command)) // write
		// formatting cmd
		for _, char := range command {
			// loop over string
			frmt_cmd += fmt.Sprintf("0x%x", char)
		}
		cmd = exec.Command("i2ctransfer", "-y", bus, fmt.Sprintf("%s@0x%x", operation, addr), frmt_cmd)
	} else {
		// reading
		cmd = exec.Command("i2ctransfer", "-y", bus, fmt.Sprintf("%s@0x%x", operation, addr))
	}
	// exec command
	var out bytes.Buffer
	var errs bytes.Buffer
	cmd.Stderr = &errs
	cmd.Stdout = &out
	if err := cmd.Run(); err != nil {
		logging.Debug(logging.DError, "I2C error getting data! %v", err)
		return "", err
	}
	return out.String(), nil
}