package io.flamenet.e2e

import kotlin.test.Test
import kotlin.test.assertEquals
import kotlin.test.assertFalse
import kotlin.test.assertTrue

/**
 * Addressing one person inside a group (§6.18).
 *
 * ⚠️ **The codec half.** The Android app does not compose or act on mentions
 * yet, but it must already understand an envelope the iPhone app sends — and,
 * more importantly, must not be made to do work by one. The bound below is the
 * part that matters today.
 */
class MentionsTest {

    @Test
    fun `mentions ride the envelope`() {
        val wire = Content.groupText("@Ada look", "g1", messageId = "m",
                                     mentions = listOf(2L, 4L))
        assertEquals(listOf(2L, 4L), Content.parse(wire).mentions)
    }

    /** Omitted when there are none, which is nearly every message. */
    @Test
    fun `a message with no mentions carries none`() {
        val wire = Content.groupText("hello", "g1", messageId = "m")
        assertFalse(wire.contains("ment"), "wrote an empty mention list: $wire")
        assertTrue(Content.parse(wire).mentions.isEmpty())
    }

    /**
     * 🔴 **Bounded.** The list comes off the wire, and a hostile sender could
     * name ten thousand ids in one envelope — the cost of which lands on every
     * recipient's device rather than theirs.
     */
    @Test
    fun `an absurd mention list is bounded`() {
        val huge = (1..10_000).joinToString(",")
        val wire = """{"fnc":1,"kind":"text","ment":[$huge],"gid":"g1","caption":"hi"}"""
        assertEquals(Content.MAXIMUM_MENTIONS, Content.parse(wire).mentions.size)
    }

    @Test
    fun `a repeated mention is counted once`() {
        val wire = """{"fnc":1,"kind":"text","ment":[2,2,2,4],"gid":"g1","caption":"hi"}"""
        assertEquals(listOf(2L, 4L), Content.parse(wire).mentions)
    }

    /** ⚠️ A malformed list must not throw — it is an ordinary message with an
     *  odd field, not a reason to drop what somebody wrote. */
    @Test
    fun `a malformed mention list does not break the message`() {
        val wire = """{"fnc":1,"kind":"text","ment":"not an array","gid":"g1","caption":"hi"}"""
        val content = Content.parse(wire)
        assertEquals("hi", content.text)
        assertTrue(content.mentions.isEmpty())
    }

    /** ⚠️ `fnc` first, like every other envelope. */
    @Test
    fun `the envelope starts with the marker`() {
        assertTrue(Content.groupText("hi", "g1", mentions = listOf(2L))
            .startsWith("{\"fnc\":1,"))
    }

    /** A mention does not stop a message being a message. */
    @Test
    fun `a mentioning message is still renderable`() {
        assertTrue(Content.parse(
            Content.groupText("@Ada hi", "g1", mentions = listOf(2L))).isRenderable)
    }
}