package com.sptmobile.messages

import org.junit.Assert.assertEquals
import org.junit.Assert.assertTrue
import org.junit.Test

class MessageThreadTest {
    // [unit->REQ-GATEWAY-THREAD]
    // The wire union parses and flattens into ONE gateway thread: every
    // endpoint's slice unified, each row tagged with its endpoint, sorted by
    // timestamp (stable on ties). This is the raw in/out log — no digest.
    @Test
    fun parsesAndFlattensUnionSortedByTimestamp() {
        val reply = """
            [
              {"endpoint":"star-1","entries":[
                {"msg_id":"a-1","ts_ms":3000,"dir":"out","from":"mobile-gw","body":"to star"}
              ]},
              {"endpoint":"agent-b","entries":[
                {"msg_id":"b-1","ts_ms":1000,"dir":"in","from":"agent-b","body":"b first"},
                {"msg_id":"b-2","ts_ms":5000,"dir":"in","from":"agent-b","body":"b second"}
              ]}
            ]
        """.trimIndent()

        val rows = MessageThread.parseThread(reply)

        assertEquals(listOf("b first", "to star", "b second"), rows.map { it.body })
        assertEquals(listOf("agent-b", "star-1", "agent-b"), rows.map { it.endpoint })
        // dir → outbound relative to the endpoint.
        assertEquals(listOf(false, true, false), rows.map { it.outbound })
    }

    // [unit->REQ-GATEWAY-THREAD]
    // Row identity is msg-id, scoped by endpoint (ids may repeat across a
    // host's endpoints); a msg-id-less row falls back to a content-stable key.
    @Test
    fun stableKeyIsEndpointScopedMsgIdWithContentFallback() {
        val group = EndpointHistoryGroup(
            endpoint = "star-1",
            entries = listOf(
                HistoryRowOf("m-1", 1000, "in", "star-1", "hello"),
                HistoryRowOf(null, 2000, "in", "star-1", "no id"),
            ),
        )
        val rows = MessageThread.flatten(listOf(group))
        assertEquals("star-1/m-1", rows[0].stableKey)
        assertTrue(rows[1].stableKey.startsWith("star-1/2000@star-1#"))
    }

    @Test
    fun emptyUnionIsEmptyThread() {
        assertTrue(MessageThread.parseThread("[]").isEmpty())
    }

    // Unknown wire fields (a newer host adding to HistoryEntry) never break the
    // parse — the union is forward-compatible.
    @Test
    fun toleratesUnknownFields() {
        val reply = """
            [{"endpoint":"e","entries":[
              {"msg_id":"x","ts_ms":1,"dir":"out","from":"g","body":"hi","json":"{}","future":42}
            ]}]
        """.trimIndent()
        val rows = MessageThread.parseThread(reply)
        assertEquals(1, rows.size)
        assertEquals("hi", rows[0].body)
    }

    private fun HistoryRowOf(
        msgId: String?,
        tsMs: Long,
        dir: String,
        from: String,
        body: String,
    ) = com.sptmobile.endpoint.HistoryRow(
        msg_id = msgId, ts_ms = tsMs, dir = dir, from = from, body = body,
    )
}