package io.flamenet.e2e

import org.json.JSONObject
import kotlin.test.Test
import kotlin.test.assertEquals
import kotlin.test.assertFalse
import kotlin.test.assertNull
import kotlin.test.assertTrue

/**
 * Handing a contact the bridge you use (§6.19).
 */
class BridgeOfferTest {
    private val line =
        "obfs4 198.51.100.7:4444 0123456789ABCDEF0123456789ABCDEF01234567 " +
            "cert=" +
            java.util.Base64
                .getEncoder()
                .encodeToString(ByteArray(52) { 0xAB.toByte() })
                .trimEnd('=') +
            " iat-mode=0"

    @Test
    fun `an offer round trips through the envelope`() {
        val parsed = Content.parse(Content.bridgeOffer(line))
        assertEquals(Content.Kind.BRIDGE, parsed.kind)
        assertEquals(line, Content.bridgeLine(parsed))
    }

    /**
     * `1`, not `true`. iOS decodes `ctl` as a number, and a boolean does not
     * merely fail to set the flag, it fails the whole envelope's decode and
     * falls through to the plain-text path, which is how an Android user once
     * sent an iPhone a bubble of raw JSON.
     */
    @Test
    fun `the control flag is the number one on the wire`() {
        val json = JSONObject(Content.bridgeOffer(line))
        assertEquals(1, json.getInt("ctl"))
        assertEquals(Content.Kind.BRIDGE, json.getString("kind"))
    }

    /**
     * What an older build does with this.
     */
    @Test
    fun `an offer is control traffic and never renders`() {
        val parsed = Content.parse(Content.bridgeOffer(line))
        assertTrue(parsed.isControl, "an offer must never become a bubble")
        assertFalse(parsed.isRenderable)
        assertTrue(Content.Kind.BRIDGE in Content.Kind.CONTROL)
    }

    /**
     * The line crosses whole.
     */
    @Test
    fun `the line is carried verbatim`() {
        val awkward = "obfs4 [2001:db8::1]:9001 ABC cert=zz+/9 iat-mode=1 sni=x.example"
        assertEquals(awkward, Content.bridgeLine(Content.parse(Content.bridgeOffer(awkward))))
    }

    /** Asked of the wrong kind, it says nothing rather than guessing. */
    @Test
    fun `another kind carries no bridge line`() {
        assertNull(Content.bridgeLine(Content.parse(Content.disappearing(60))))
        assertNull(Content.bridgeLine(Content.parse("just a message")))
    }

    /**
     * An empty or whitespace line is not an offer.
     */
    @Test
    fun `an empty line is not an offer`() {
        assertNull(Content.bridgeLine(Content.parse(Content.bridgeOffer("   "))))
    }

    /**
     * The engine validates nothing, deliberately.
     */
    @Test
    fun `a malformed line still arrives, to be judged where it can be explained`() {
        val junk = "obfs4 this-is-not-a-bridge-line"
        assertEquals(junk, Content.bridgeLine(Content.parse(Content.bridgeOffer(junk))))
    }
}