package jp.juggler.util

//import it.sephiroth.android.library.exif2.ExifInterface
import android.content.Context
import android.graphics.*
import android.net.Uri
import androidx.annotation.StringRes
import androidx.exifinterface.media.ExifInterface
import java.io.FileNotFoundException
import java.io.InputStream
import kotlin.math.max
import kotlin.math.sqrt

private val log = LogCategory("BitmapUtils")

fun InputStream.imageOrientation(): Int? =
    try {
        ExifInterface(this)
            //			.readExif(
            //				this@imageOrientation,
            //				ExifInterface.Options.OPTION_IFD_0
            //					or ExifInterface.Options.OPTION_IFD_1
            //					or ExifInterface.Options.OPTION_IFD_EXIF
            //			)
            .getAttributeInt(ExifInterface.TAG_ORIENTATION, -1)
            .takeIf { it >= 0 }
    } catch (ex: Throwable) {
        log.w(ex, "imageOrientation: exif parse failed.")
        null
    }

// 回転情報の値に合わせて、wとhを入れ替える
fun rotateSize(orientation: Int?, w: Float, h: Float): PointF =
    when (orientation) {
        5, 6, 7, 8 -> PointF(h, w)
        else -> PointF(w, h)
    }

// 回転情報を解決するようにmatrixに回転を加える
fun Matrix.resolveOrientation(orientation: Int?): Matrix {
    when (orientation) {
        2 -> postScale(1f, -1f)
        3 -> postRotate(180f)
        4 -> postScale(-1f, 1f)

        5 -> {
            postScale(1f, -1f)
            postRotate(-90f)
        }

        6 -> postRotate(90f)

        7 -> {
            postScale(1f, -1f)
            postRotate(90f)
        }

        8 -> postRotate(-90f)
    }
    return this
}

enum class ResizeType {
    // リサイズなし
    None,

    // 長辺がsize以下になるようリサイズ
    LongSide,

    // 平方ピクセルが size*size 以下になるようリサイズ
    SquarePixel,
}

class ResizeConfig(
    val type: ResizeType,
    val size: Int,
    @StringRes val extraStringId: Int = 0,
) {
    val spec: String
        get() = when (type) {
            ResizeType.None -> type.toString()
            else -> "$type,$size"
        }

    override fun toString() = "ResizeConfig($spec)"
}

private fun PointF.limitBySqPixel(aspect: Float, maxSqPixels: Float): PointF {
    val currentSqPixels = x * y
    return when {
        maxSqPixels <= 0 -> this
        currentSqPixels <= maxSqPixels -> this
        else -> {
            val y = sqrt(maxSqPixels / aspect)
            val x = aspect * y
            PointF(x, y)
        }
    }
}

fun createResizedBitmap(
    context: Context,
    uri: Uri,
    sizeLongSide: Int,
    serverMaxSqPixel: Int? = null,
    skipIfNoNeedToResizeAndRotate: Boolean = false,
) = createResizedBitmap(
    context,
    uri,
    when {
        sizeLongSide <= 0 -> ResizeConfig(ResizeType.None, 0)
        else -> ResizeConfig(ResizeType.LongSide, sizeLongSide)
    },
    serverMaxSqPixel = serverMaxSqPixel,
    skipIfNoNeedToResizeAndRotate = skipIfNoNeedToResizeAndRotate
)

fun createResizedBitmap(
    context: Context,

    // contentResolver.openInputStream に渡すUri
    uri: Uri,

    // リサイズ指定
    resizeConfig: ResizeConfig,

    // サーバ側の最大平方ピクセル
    serverMaxSqPixel: Int? = null,

    // 真の場合、リサイズも回転も必要ないならnullを返す
    skipIfNoNeedToResizeAndRotate: Boolean = false,

    ): Bitmap? {

    try {

        val orientation: Int? = context.contentResolver.openInputStream(uri)?.use {
            it.imageOrientation()
        }

        // 画像のサイズを調べる
        val options = BitmapFactory.Options()
        options.inJustDecodeBounds = true
        options.inScaled = false
        options.outWidth = 0
        options.outHeight = 0
        context.contentResolver.openInputStream(uri)?.use {
            BitmapFactory.decodeStream(it, null, options)
        }

        var srcWidth = options.outWidth
        var srcHeight = options.outHeight
        if (srcWidth <= 0 || srcHeight <= 0) {
            context.showToast(false, "could not get image bounds.")
            return null
        }

        // 回転後のサイズ
        val srcSize = rotateSize(orientation, srcWidth.toFloat(), srcHeight.toFloat())
        val aspect = srcSize.x / srcSize.y

        /// 出力サイズの計算
        val sizeSpec = resizeConfig.size.toFloat()
        var dstSize: PointF = when (resizeConfig.type) {

            ResizeType.None -> srcSize

            ResizeType.LongSide ->
                if (max(srcSize.x, srcSize.y) <= resizeConfig.size) {
                    srcSize
                } else {
                    if (aspect >= 1f) {
                        PointF(
                            resizeConfig.size.toFloat(),
                            sizeSpec / aspect
                        )
                    } else {
                        PointF(
                            sizeSpec * aspect,
                            resizeConfig.size.toFloat()
                        )
                    }
                }

            ResizeType.SquarePixel -> srcSize.limitBySqPixel(aspect, sizeSpec * sizeSpec)
        }

        if (serverMaxSqPixel != null && serverMaxSqPixel > 0) {
            dstSize = dstSize.limitBySqPixel(aspect, serverMaxSqPixel.toFloat())
        }

        val dstSizeInt = Point(
            max(1, (dstSize.x + 0.5f).toInt()),
            max(1, (dstSize.y + 0.5f).toInt())
        )

        val resizeRequired = dstSizeInt.x != srcSize.x.toInt() || dstSizeInt.y != srcSize.y.toInt()

        log.i("createResizedBitmap: rc=${
            resizeConfig
        }, src=${
            srcSize
        }, dst=${
            dstSizeInt
        }, ori=${
            orientation
        }, resizeRequired=${
            resizeRequired
        }")

        // リサイズも回転も必要がない場合
        if (skipIfNoNeedToResizeAndRotate &&
            (orientation == null || orientation == 1) &&
            !resizeRequired
        ) {
            log.w("createResizedBitmap: no need to resize or rotate.")
            return null
        }

        // 長辺
        val dstMax = max(dstSize.x, dstSize.y).toInt()

        // inSampleSizeを計算
        var bits = 0
        var x = max(srcSize.x, srcSize.y).toInt()
        while (x > 512 && x > dstMax * 2) {
            ++bits
            x = x shr 1
        }
        options.inJustDecodeBounds = false
        options.inSampleSize = 1 shl bits

        val sourceBitmap: Bitmap? =
            context.contentResolver.openInputStream(uri)?.use {
                BitmapFactory.decodeStream(it, null, options)
            }

        if (sourceBitmap == null) {
            context.showToast(false, "could not decode image.")
            return null
        }
        try {
            // サンプル数が変化している
            srcWidth = options.outWidth
            srcHeight = options.outHeight
            val scale = dstMax.toFloat() / max(srcWidth, srcHeight)

            val matrix = Matrix().apply {
                reset()

                // 画像の中心が原点に来るようにして
                postTranslate(srcWidth * -0.5f, srcHeight * -0.5f)

                // スケーリング
                postScale(scale, scale)

                // 回転情報があれば回転
                resolveOrientation(orientation)

                // 表示領域に埋まるように平行移動
                postTranslate(dstSizeInt.x.toFloat() * 0.5f, dstSizeInt.y.toFloat() * 0.5f)
            }

            // 出力用Bitmap作成
            var dst: Bitmap? =
                Bitmap.createBitmap(dstSizeInt.x, dstSizeInt.y, Bitmap.Config.ARGB_8888)
            try {
                return if (dst == null) {
                    context.showToast(false, "bitmap creation failed.")
                    null
                } else {
                    val canvas = Canvas(dst)
                    val paint = Paint()
                    paint.isFilterBitmap = true
                    canvas.drawBitmap(sourceBitmap, matrix, paint)
                    log.d("createResizedBitmap: resized to ${dstSizeInt.x}x${dstSizeInt.y}")
                    val tmp = dst
                    dst = null
                    tmp
                }
            } finally {
                dst?.recycle()
            }
        } finally {
            sourceBitmap.recycle()
        }
    } catch (ex: FileNotFoundException) {
        log.w(ex, "not found. $uri")
    } catch (ex: SecurityException) {
        log.w(ex, "maybe we need pick up image again.")
    } catch (ex: Throwable) {
        log.e(ex, "createResizedBitmap failed.")
    }
    return null
}