//
//  SSEParserTests.swift
//  Zyquo Atlas
//
//  Author: Simon-Pierre Boucher
//  Mail: contact@spboucher.ai
//

import Testing
@testable import ZyquoAtlas

@Suite struct SSEParserTests {
    private func parse(_ lines: [String]) -> [SSEEvent] {
        var parser = SSEParser()
        var events: [SSEEvent] = []
        for line in lines {
            if let event = parser.consume(line: line) { events.append(event) }
        }
        if let last = parser.consume(line: "") { events.append(last) }
        return events
    }

    @Test func openAIStyleDataEvents() {
        let events = parse([
            #"data: {"choices":[{"delta":{"content":"Hel"}}]}"#,
            "",
            #"data: {"choices":[{"delta":{"content":"lo"}}]}"#,
            "",
            "data: [DONE]",
            "",
        ])
        #expect(events.count == 3)
        #expect(events[0].data.contains("Hel"))
        #expect(events[2].data == "[DONE]")
        #expect(events[0].event == nil)
    }

    @Test func anthropicNamedEvents() {
        let events = parse([
            "event: message_start",
            #"data: {"type":"message_start","message":{"usage":{"input_tokens":9}}}"#,
            "",
            "event: content_block_delta",
            #"data: {"type":"content_block_delta","delta":{"type":"text_delta","text":"OK"}}"#,
            "",
            "event: message_stop",
            #"data: {"type":"message_stop"}"#,
            "",
        ])
        #expect(events.count == 3)
        #expect(events[0].event == "message_start")
        #expect(events[1].event == "content_block_delta")
        #expect(events[2].event == "message_stop")
    }

    @Test func commentAndKeepAliveLinesIgnored() {
        let events = parse([
            ": keep-alive",
            "",
            #"data: {"x":1}"#,
            "",
            ": another comment",
            "",
        ])
        #expect(events.count == 1)
        #expect(events[0].data == #"{"x":1}"#)
    }

    @Test func multiLineDataJoined() {
        let events = parse([
            "data: line1",
            "data: line2",
            "",
        ])
        #expect(events.count == 1)
        #expect(events[0].data == "line1\nline2")
    }

    @Test func trailingEventWithoutBlankLineFlushed() {
        var parser = SSEParser()
        #expect(parser.consume(line: "data: tail") == nil)
        let flushed = parser.consume(line: "")
        #expect(flushed?.data == "tail")
    }
}