package com.peachpasswords.vault

import kotlinx.coroutines.runBlocking
import kotlinx.serialization.json.Json
import org.junit.Assert.assertEquals
import org.junit.Assert.assertFalse
import org.junit.Assert.assertTrue
import org.junit.Test

/** In-memory [VaultStorage] for exercising last4 derivation on save (MF-3). */
private class CardFakeStorage : VaultStorage {
    private var slotA: StoredVault? = null
    private var slotB: String? = null
    private var ver: Long = 0
    private var settings = VaultSettings()
    override fun loadSlotA() = slotA
    override fun hasVault() = slotA != null
    override fun writeSlotA(slot: StoredVault): Boolean { slotA = slot; return true }
    override fun writeSlotB(blobBase64: String): Boolean { slotB = blobBase64; return true }
    private var decoy: StoredVault? = null
    override fun loadDecoySlot() = decoy
    override fun writeDecoySlot(slot: StoredVault): Boolean { decoy = slot; return true }
    override fun hasDecoySlot() = decoy != null
    override fun clearDecoySlot() { decoy = null }
    override fun version() = ver
    override fun stampLocalMutation(): Long { ver = maxOf(System.currentTimeMillis(), ver + 1); return ver }
    override fun loadSettings() = settings
    override fun writeSettings(s: VaultSettings): Boolean { settings = s; return true }
    override fun clearVault(): Boolean { slotA = null; slotB = null; ver = 0; settings = VaultSettings(); return true }
}

class CardSerializationTest {
    private val json = Json { encodeDefaults = true }

    @Test fun card_network_serializes_as_browser_key() {
        val card = VaultEntry(
            id = "c1", type = "card", title = "Visa", cardNumber = "4242424242424242",
            cardNetwork = "visa", last4 = "4242", createdAt = 0, modifiedAt = 0,
        )
        val encoded = json.encodeToString(VaultEntry.serializer(), card)
        assertTrue("serializes cardNetwork as \"network\"", encoded.contains("\"network\":\"visa\""))
        assertTrue("serializes last4 explicitly", encoded.contains("\"last4\":\"4242\""))
        assertFalse("never emits the Android-only key name", encoded.contains("cardNetwork"))
    }

    @Test fun network_and_last4_round_trip_from_browser_keys() {
        val wire = """{"id":"c1","title":"Visa","type":"card","network":"visa","last4":"4242","createdAt":0,"modifiedAt":0}"""
        val decoded = json.decodeFromString(VaultEntry.serializer(), wire)
        assertEquals("visa", decoded.cardNetwork)
        assertEquals("4242", decoded.last4)
    }

    @Test fun last4_is_derived_on_save() = runBlocking {
        val repo = VaultRepository(CardFakeStorage())
        repo.createVault("correct horse battery staple")
        val saved = repo.addEntry(
            VaultEntry(id = "", type = "card", title = "My Card", cardNumber = "4111 1111 1111 1234", createdAt = 0, modifiedAt = 0),
        )
        assertEquals("derives last4 from the PAN on save", "1234", saved.last4)

        val updated = repo.updateEntry(saved.copy(cardNumber = "5555 5555 5555 4321"))
        assertEquals("re-derives last4 on update", "4321", updated.last4)
    }

    @Test fun non_card_entry_has_no_last4() = runBlocking {
        val repo = VaultRepository(CardFakeStorage())
        repo.createVault("correct horse battery staple")
        val saved = repo.addEntry(VaultEntry(id = "", type = "login", title = "GitHub", password = "pw", createdAt = 0, modifiedAt = 0))
        assertEquals(null, saved.last4)
    }
}