package com.peachpasswords.codex

import android.graphics.Bitmap
import android.graphics.Color
import com.google.zxing.BarcodeFormat
import com.google.zxing.BinaryBitmap
import com.google.zxing.DecodeHintType
import com.google.zxing.EncodeHintType
import com.google.zxing.LuminanceSource
import com.google.zxing.RGBLuminanceSource
import com.google.zxing.aztec.AztecReader
import com.google.zxing.aztec.AztecWriter
import com.google.zxing.common.GlobalHistogramBinarizer
import com.google.zxing.common.HybridBinarizer

/** Aztec encode/decode for one Codex chunk, via ZXing. */
object CodexAztec {

    /** Render an envelope JSON string into a square monochrome Aztec [Bitmap]. */
    fun encode(content: String, sizePx: Int = 320): Bitmap {
        val hints = mapOf(EncodeHintType.ERROR_CORRECTION to AZTEC_ECC_PERCENT)
        val matrix = AztecWriter().encode(content, BarcodeFormat.AZTEC, sizePx, sizePx, hints)
        val w = matrix.width
        val h = matrix.height
        val pixels = IntArray(w * h)
        for (y in 0 until h) {
            val row = y * w
            for (x in 0 until w) {
                pixels[row + x] = if (matrix[x, y]) Color.BLACK else Color.WHITE
            }
        }
        return Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888).apply { setPixels(pixels, 0, w, 0, 0, w, h) }
    }

    /**
     * Decode an Aztec code from a tightly-cropped [Bitmap]. A rendered,
     * cropped single code decodes most reliably with PURE_BARCODE (skip the
     * locate-in-scene search); fall back to the full detector for codes that
     * carry surrounding bleed. Null if neither reads.
     */
    fun decode(bitmap: Bitmap): String? {
        val w = bitmap.width
        val h = bitmap.height
        val pixels = IntArray(w * h)
        bitmap.getPixels(pixels, 0, w, 0, 0, w, h)
        val source: LuminanceSource = RGBLuminanceSource(w, h, pixels)
        val pure = mapOf(DecodeHintType.PURE_BARCODE to true, DecodeHintType.TRY_HARDER to true)
        val scene = mapOf(DecodeHintType.TRY_HARDER to true)
        // Cross both binarizers (Hybrid is adaptive; Global handles flat,
        // evenly-lit renders) with both detector modes — marginal codes that
        // miss one combination usually read on another.
        val attempts = listOf(
            BinaryBitmap(HybridBinarizer(source)) to pure,
            BinaryBitmap(HybridBinarizer(source)) to scene,
            BinaryBitmap(GlobalHistogramBinarizer(source)) to pure,
        )
        for ((binarizer, hints) in attempts) {
            try {
                return AztecReader().decode(binarizer, hints).text
            } catch (_: Exception) {
                // try next strategy
            }
        }
        return null
    }
}