package goadb

import (
	"bytes"
	"fmt"
	"image"
	"image/color"
	"image/png"
	"strconv"
	"strings"

	"github.com/otiai10/gosseract/v2"
)

// Get the state of the screen (Asleep/Awake)
func (d *Device) GetScreenState() (string, error) {
	data, err := d.RunCommand("shell dumpsys power | grep mWakefulness | head -n1")
	if err != nil {
		return "", err
	}
	state := strings.Split(string(data), "=")[1]
	return state, err
}

// Toggle the screen by simulating a press of the power button
func (d *Device) ToggleScreen() error {
	_, err := d.RunCommand("shell input keyevent 26")
	return err
}

// Tap on a location on the screen
func (d *Device) TapScreen(x int, y int) error {
	_, err := d.RunCommand(fmt.Sprintf("shell input tap %d %d", x, y))
	return err
}

// Get the resolution of the screen
func (d *Device) GetScreenResolution() (int, int, error) {

	//Not yet set on the device so use adb to retrieve it
	if d.Screenx == 0 || d.Screeny == 0 {

		data, err := d.RunCommand("shell wm size")
		res := strings.Split(string(data), ":")[1]
		dimensions := strings.Split(res, "x")

		if len(dimensions) != 2 {
			return -1, -1, fmt.Errorf("invalid dimensions for screen")
		}

		x, err := strconv.Atoi(strings.TrimSpace(dimensions[0]))
		if err != nil {
			return -1, -1, err
		}

		y, err := strconv.Atoi(strings.TrimSpace(dimensions[1]))
		if err != nil {
			return -1, -1, err
		}

		d.Screenx = x
		d.Screeny = y

		return x, y, err
	}

	return d.Screenx, d.Screeny, nil
}

func (d *Device) GetScreenText(xStart int, xEnd int, yStart int, yEnd int, whitelist string, multiline bool) (string, error) {
    data, err := d.RunCommand("exec-out screencap -p")
    if err != nil {
        return "", fmt.Errorf("failed to take screenshot: %w", err)
    }

    img, err := png.Decode(bytes.NewReader(data))
    if err != nil {
        return "", fmt.Errorf("failed to decode PNG: %w", err)
    }

    rect := image.Rect(0, 0, xEnd-xStart, yEnd-yStart)
    cropped := image.NewRGBA(rect)
    for y := yStart; y < yEnd; y++ {
        for x := xStart; x < xEnd; x++ {
            cropped.Set(x-xStart, y-yStart, img.At(x, y))
        }
    }

    // Convert to grayscale
    gray := image.NewGray(rect)
    for y := 0; y < rect.Dy(); y++ {
        for x := 0; x < rect.Dx(); x++ {
            gray.Set(x, y, color.GrayModel.Convert(cropped.At(x, y)))
        }
    }

    // Apply simple mean-based adaptive thresholding
    binarized := image.NewGray(rect)
    window := 15 // size of local region
    for y := 0; y < rect.Dy(); y++ {
        for x := 0; x < rect.Dx(); x++ {
            var sum int
            var count int
            for dy := -window / 2; dy <= window/2; dy++ {
                for dx := -window / 2; dx <= window/2; dx++ {
                    xx := x + dx
                    yy := y + dy
                    if xx >= 0 && xx < rect.Dx() && yy >= 0 && yy < rect.Dy() {
                        sum += int(gray.GrayAt(xx, yy).Y)
                        count++
                    }
                }
            }
            mean := sum / count
            if int(gray.GrayAt(x, y).Y) < mean-10 {
                binarized.SetGray(x, y, color.Gray{Y: 0})
            } else {
                binarized.SetGray(x, y, color.Gray{Y: 255})
            }
        }
    }

    var buf bytes.Buffer
    if err := png.Encode(&buf, binarized); err != nil {
        return "", fmt.Errorf("failed to encode image: %w", err)
    }

    client := gosseract.NewClient()
    defer client.Close()
    client.SetImageFromBytes(buf.Bytes())
    client.SetWhitelist(whitelist)
    if multiline {
        client.SetPageSegMode(gosseract.PSM_AUTO)
    } else {
        client.SetPageSegMode(gosseract.PSM_SINGLE_BLOCK)
    }

    text, err := client.Text()
    if err != nil {
        return "", fmt.Errorf("tesseract error: %w", err)
    }
    return text, nil
}