Image Similarity Detection & Grouping via pHash

package com.wefamily.papa.ui.similarity

// ... 导入省略 ...
import androidx.lifecycle.lifecycleScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext

data class SimilarityGroup(val mainImageUri: String, val similarImages: MutableList<String> = mutableListOf())

class ImageSimilarityActivity : AppCompatActivity() {
    private lateinit var adapter: SimilarityAdapter

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_similarity)

        adapter = SimilarityAdapter()
        findViewById<RecyclerView>(R.id.recyclerView).adapter = adapter

        // 模拟从本地获取的相册 URI 列表，开始检测
        val imageUris = listOf("file:///sdcard/img1.jpg", "file:///sdcard/img2.jpg" /* ... */)
        processImages(imageUris)
    }

    private fun processImages(paths: List<String>) {
        lifecycleScope.launch(Dispatchers.Default) {
            val hashMap = mutableMapOf<String, Long>()
            // 1. 计算所有图片的 Hash
            for (path in paths) {
                val bitmap = BitmapFactory.decodeFile(path.replace("file://", ""))
                if (bitmap != null) {
                    hashMap[path] = ImageHashUtils.calculateHash(bitmap)
                }
            }

            // 2. 分组逻辑 (距离 <= 5 视为相似)
            val groups = mutableListOf<SimilarityGroup>()
            val processed = mutableSetOf<String>()

            for ((path1, hash1) in hashMap) {
                if (processed.contains(path1)) continue
                val group = SimilarityGroup(path1)
                processed.add(path1)

                for ((path2, hash2) in hashMap) {
                    if (!processed.contains(path2)) {
                        val distance = ImageHashUtils.getHammingDistance(hash1, hash2)
                        if (distance <= 5) {
                            group.similarImages.add(path2)
                            processed.add(path2)
                        }
                    }
                }
                if (group.similarImages.isNotEmpty()) {
                    groups.add(group) // 仅展示有重复/相似内容的组
                }
            }

            // 3. 主线程刷新 UI
            withContext(Dispatchers.Main) {
                adapter.submitList(groups)
            }
        }
    }
}