package farm.hobbs.kioskbrowser

import org.junit.Assert.*
import org.junit.Test

/**
 * Unit tests for PIN security hashing
 * Note: These tests use a mock implementation since android.util.Base64
 * is not available in unit tests. The actual implementation uses Android's Base64.
 */
class PinSecurityTest {

    // Simple test implementation for unit tests
    private fun simpleHash(pin: String): String {
        // SHA-256 hash without salt for testing verification logic
        val digest = java.security.MessageDigest.getInstance("SHA-256")
        val hash = digest.digest(pin.toByteArray())
        return hash.joinToString("") { "%02x".format(it) }
    }

    @Test
    fun `same PIN produces same hash with same salt`() {
        val pin = "1234"
        val hash1 = simpleHash(pin)
        val hash2 = simpleHash(pin)
        assertEquals(hash1, hash2)
    }

    @Test
    fun `different PINs produce different hashes`() {
        val hash1 = simpleHash("1234")
        val hash2 = simpleHash("5678")
        assertNotEquals(hash1, hash2)
    }

    @Test
    fun `hash is not equal to plain PIN`() {
        val pin = "1234"
        val hash = simpleHash(pin)
        assertNotEquals(pin, hash)
    }

    @Test
    fun `hash has expected length for SHA-256`() {
        val hash = simpleHash("1234")
        // SHA-256 produces 64 hex characters
        assertEquals(64, hash.length)
    }

    @Test
    fun `empty PIN can be hashed`() {
        val hash = simpleHash("")
        assertNotNull(hash)
        assertEquals(64, hash.length)
    }

    @Test
    fun `long PIN can be hashed`() {
        val longPin = "12345678901234567890"
        val hash = simpleHash(longPin)
        assertNotNull(hash)
        assertEquals(64, hash.length)
    }

    @Test
    fun `isHashed detects colon-separated format`() {
        assertTrue(isHashedFormat("abc123:def456"))
        assertTrue(isHashedFormat("salt:hash"))
    }

    @Test
    fun `isHashed rejects plain text`() {
        assertFalse(isHashedFormat("1234"))
        assertFalse(isHashedFormat("plaintext"))
    }

    @Test
    fun `isHashed rejects malformed formats`() {
        assertFalse(isHashedFormat("no-colon"))
        assertFalse(isHashedFormat(""))
    }

    // Helper matching PinSecurity.isHashed logic
    private fun isHashedFormat(value: String): Boolean {
        return value.contains(":") && value.split(":").size == 2
    }
}