package com.pantrist.ml

import android.util.Base64
import com.getcapacitor.*
import com.getcapacitor.annotation.CapacitorPlugin
import java.io.IOException
import android.graphics.BitmapFactory
import android.graphics.Point
import android.graphics.Rect

import com.google.mlkit.vision.common.InputImage
import com.google.mlkit.vision.text.TextRecognition
import com.google.mlkit.vision.text.latin.TextRecognizerOptions

@CapacitorPlugin
class CapacitorPluginMlKitTextRecognition : Plugin() {
  @PluginMethod
  fun detectText(call: PluginCall) {
    val recognizer = TextRecognition.getClient(TextRecognizerOptions.DEFAULT_OPTIONS)

    val encodedImage = call.getString("base64Image")
    if (encodedImage == null) {
      call.reject("No image is given!")
      return
    }
    val rotation = call.getInt("rotation") ?: 0

    val image: InputImage
    try {
      val decodedString: ByteArray = Base64.decode(encodedImage, Base64.DEFAULT);
      val decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.size)
      if (decodedByte == null) {
        call.reject("Decoded image is null")
        return
      }
      image = InputImage.fromBitmap(decodedByte, rotation)
    } catch (e: IOException) {
      call.reject("Unable to parse image")
      return
    }

    recognizer.process(image)
      .addOnSuccessListener { visionText ->
        val ret = JSObject()
        ret.put("text", visionText.text)

        val textBlocks = JSArray()
        visionText.textBlocks.forEach { block ->
          val blockObject = JSObject();
          blockObject.put("text", block.text)
          blockObject.put("boundingBox", parseRectToJsObject(block.boundingBox))
          blockObject.put("recognizedLanguage", block.recognizedLanguage)
          blockObject.put("cornerPoints", parseCornerPointsToJsObject(block.cornerPoints))

          val linesArray = JSArray()
          block.lines.forEach { line ->
            val lineObject = JSObject()
            lineObject.put("text", line.text)
            lineObject.put("boundingBox", parseRectToJsObject(line.boundingBox))
            lineObject.put("recognizedLanguage", line.recognizedLanguage)
            lineObject.put("cornerPoints", parseCornerPointsToJsObject(line.cornerPoints))

            val elementArray = JSArray()
            line.elements.forEach { element ->
              val elementObject = JSObject()
              elementObject.put("text", element.text)
              elementObject.put("boundingBox", parseRectToJsObject(element.boundingBox))
              elementObject.put("recognizedLanguage", line.recognizedLanguage)
              elementObject.put("cornerPoints", parseCornerPointsToJsObject(element.cornerPoints))
              elementArray.put(elementObject)
            }
            lineObject.put("elements", elementArray)
            linesArray.put(lineObject)
          }
          blockObject.put("lines", linesArray)
          textBlocks.put(blockObject)
        };
        ret.put("blocks", textBlocks)

        call.resolve(ret)
      }
      .addOnFailureListener { e ->
        call.reject("Unable process image!", e)
      }
  }

  private fun parseRectToJsObject(rect: Rect?): JSObject? {
    if (rect == null) {
      return null
    }

    val returnObject = JSObject();
    returnObject.put("left", rect.left)
    returnObject.put("top", rect.top)
    returnObject.put("right", rect.right)
    returnObject.put("bottom", rect.bottom)
    return returnObject;
  }

  private fun parseCornerPointsToJsObject(cornerPoints: Array<Point>?): JSObject? {
    if (cornerPoints == null || cornerPoints.size != 4) {
      return null;
    }
    val res = JSObject();
    res.put("topLeft", pointToJsObject(cornerPoints[0]));
    res.put("topRight", pointToJsObject(cornerPoints[1]));
    res.put("bottomRight", pointToJsObject(cornerPoints[2]));
    res.put("bottomLeft", pointToJsObject(cornerPoints[3]));
    return res;
  }

  private fun pointToJsObject(pt: Point): JSObject {
    val res = JSObject();
    res.put("x", pt.x.toDouble());
    res.put("y", pt.y.toDouble());
    return res;
  }
}