import Foundation enum CodexCompactSubagentFixture {    typealias Usage = (input: Int, cached: Int, output: Int)     struct Child {        let sessionID: String        let parentID: String        let leafModel: String        let prefix: Usage        let suffix: Usage        let preBoundaryLast: Usage?    }     static func parentContents(        env: CostUsageTestEnvironment,        day: Date,        sessionID: String,        model: String,        totals: Usage) throws -> String    {        try env.jsonl([            [                "type": "session_meta",                "timestamp": env.isoString(for: day.addingTimeInterval(-2)),                "payload": ["id": sessionID],            ],            self.turnContext(                timestamp: env.isoString(for: day.addingTimeInterval(-2)),                model: model),            self.tokenCount(                timestamp: env.isoString(for: day.addingTimeInterval(-1)),                model: model,                total: totals,                last: totals),        ])    }     static func childContents(        env: CostUsageTestEnvironment,        day: Date,        fixture: Child) throws -> String    {        let forkTimestamp = env.isoString(for: day)        var lines: [[String: Any]] = [            [                "type": "session_meta",                "timestamp": forkTimestamp,                "payload": [                    "id": fixture.sessionID,                    "forked_from_id": fixture.parentID,                    "timestamp": forkTimestamp,                    "source": [                        "subagent": [                            "thread_spawn": ["parent_thread_id": fixture.parentID],                        ],                    ],                ],            ],            self.tokenCountWithoutModel(                timestamp: env.isoString(for: day.addingTimeInterval(0.1)),                total: fixture.prefix,                last: fixture.prefix),        ]        if let preBoundaryLast = fixture.preBoundaryLast {            lines.append(self.tokenCountWithoutModel(                timestamp: env.isoString(for: day.addingTimeInterval(0.2)),                last: preBoundaryLast))        }        lines.append(contentsOf: [            self.turnContext(                timestamp: env.isoString(for: day.addingTimeInterval(1)),                model: fixture.leafModel),            [                "type": "inter_agent_communication_metadata",                "timestamp": env.isoString(for: day.addingTimeInterval(1)),                "payload": ["trigger_turn": true],            ],            self.tokenCountWithoutModel(                timestamp: env.isoString(for: day.addingTimeInterval(2)),                total: (                    input: fixture.prefix.input + fixture.suffix.input,                    cached: fixture.prefix.cached + fixture.suffix.cached,                    output: fixture.prefix.output + fixture.suffix.output),                last: fixture.suffix),        ])        return try env.jsonl(lines)    }     static func tokenCount(        timestamp: String,        model: String,        total: Usage? = nil,        last: Usage? = nil) -> [String: Any]    {        var info: [String: Any] = ["model": model]        if let total {            info["total_token_usage"] = self.usagePayload(total)        }        if let last {            info["last_token_usage"] = self.usagePayload(last)        }        return [            "type": "event_msg",            "timestamp": timestamp,            "payload": [                "type": "token_count",                "info": info,            ],        ]    }     private static func turnContext(timestamp: String, model: String) -> [String: Any] {        [            "type": "turn_context",            "timestamp": timestamp,            "payload": ["model": model],        ]    }     private static func tokenCountWithoutModel(        timestamp: String,        total: Usage? = nil,        last: Usage? = nil) -> [String: Any]    {        var info: [String: Any] = [:]        if let total {            info["total_token_usage"] = self.usagePayload(total)        }        if let last {            info["last_token_usage"] = self.usagePayload(last)        }        return [            "type": "event_msg",            "timestamp": timestamp,            "payload": [                "type": "token_count",                "info": info,            ],        ]    }     private static func usagePayload(_ usage: Usage) -> [String: Any] {        [            "input_tokens": usage.input,            "cached_input_tokens": usage.cached,            "output_tokens": usage.output,        ]    }}