selfware 0.6.2

//! Aggregated benchmark report with throughput and latency statistics.

use serde::{Deserialize, Serialize};

use super::config::HarnessConfig;
use super::task::StreamResult;

/// Complete benchmark harness report.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct HarnessReport {
    /// ISO 8601 timestamp of the run.
    pub timestamp: String,
    /// Model identifier.
    pub model: String,
    /// Endpoint used.
    pub endpoint: String,
    /// Concurrency level.
    pub max_concurrent: usize,
    /// Total tasks submitted.
    pub tasks_total: usize,
    /// Tasks that passed evaluation.
    pub tasks_passed: usize,
    /// Tasks that failed (errors or eval failure).
    pub tasks_failed: usize,
    /// Total prompt tokens consumed.
    pub total_prompt_tokens: u64,
    /// Total completion tokens generated.
    pub total_completion_tokens: u64,
    /// Aggregate tokens/second (completion tokens / wall-clock seconds).
    pub tokens_per_sec: f64,
    /// Latency percentiles in milliseconds.
    pub latency_p50_ms: u64,
    pub latency_p95_ms: u64,
    pub latency_p99_ms: u64,
    /// Average latency in milliseconds.
    pub latency_avg_ms: f64,
    /// Min/max latency.
    pub latency_min_ms: u64,
    pub latency_max_ms: u64,
    /// Average evaluation score across all tasks that produced an eval result
    /// (not only passed ones — failed evals contribute their score too).
    pub avg_score: f64,
    /// Total wall-clock duration in seconds.
    pub total_duration_secs: f64,
    /// Error rate (0.0–1.0).
    pub error_rate: f64,
    /// Per-task results.
    pub results: Vec<StreamResult>,
}

impl HarnessReport {
    /// Build a report from collected stream results.
    pub fn from_results(
        config: &HarnessConfig,
        mut results: Vec<StreamResult>,
        total_duration_secs: f64,
    ) -> Self {
        let tasks_total = results.len();
        let tasks_passed = results.iter().filter(|r| r.success).count();
        let tasks_failed = tasks_total - tasks_passed;

        let total_prompt_tokens: u64 = results.iter().map(|r| r.prompt_tokens).sum();
        let total_completion_tokens: u64 = results.iter().map(|r| r.completion_tokens).sum();

        let tokens_per_sec = if total_duration_secs > 0.0 {
            total_completion_tokens as f64 / total_duration_secs
        } else {
            0.0
        };

        // Latency stats — over TRANSPORT-successful requests only (the request
        // completed and returned a well-formed response). This is independent
        // of evaluation: a timely but wrong answer is still a valid latency
        // sample, whereas a connection error / HTTP error / parse failure is
        // not. Filtering on eval-success instead would report 0 latency when
        // every answer happens to be wrong.
        let mut latencies: Vec<u64> = results
            .iter()
            .filter(|r| r.transport_succeeded)
            .map(|r| r.latency_ms)
            .collect();
        latencies.sort_unstable();

        let latency_p50_ms = percentile(&latencies, 50);
        let latency_p95_ms = percentile(&latencies, 95);
        let latency_p99_ms = percentile(&latencies, 99);
        let latency_avg_ms = if latencies.is_empty() {
            0.0
        } else {
            latencies.iter().sum::<u64>() as f64 / latencies.len() as f64
        };
        let latency_min_ms = latencies.first().copied().unwrap_or(0);
        let latency_max_ms = latencies.last().copied().unwrap_or(0);

        // Average score across tasks with eval results
        let scored: Vec<f64> = results
            .iter()
            .filter_map(|r| r.eval.as_ref().map(|e| e.score))
            .collect();
        let avg_score = if scored.is_empty() {
            0.0
        } else {
            scored.iter().sum::<f64>() / scored.len() as f64
        };

        let error_rate = if tasks_total > 0 {
            tasks_failed as f64 / tasks_total as f64
        } else {
            0.0
        };

        // Sort results by task_id for deterministic output
        results.sort_by(|a, b| a.task_id.cmp(&b.task_id));

        let timestamp = chrono::Utc::now().to_rfc3339();

        Self {
            timestamp,
            model: config.model.clone(),
            endpoint: config.endpoint.clone(),
            max_concurrent: config.max_concurrent,
            tasks_total,
            tasks_passed,
            tasks_failed,
            total_prompt_tokens,
            total_completion_tokens,
            tokens_per_sec,
            latency_p50_ms,
            latency_p95_ms,
            latency_p99_ms,
            latency_avg_ms,
            latency_min_ms,
            latency_max_ms,
            avg_score,
            total_duration_secs,
            error_rate,
            results,
        }
    }

    /// Serialize to JSON string.
    pub fn to_json(&self) -> serde_json::Result<String> {
        serde_json::to_string_pretty(self)
    }

    /// Render as a Markdown summary.
    pub fn to_markdown(&self) -> String {
        let mut md = String::new();

        md.push_str(&format!("# Benchmark Report — {}\n", self.model));
        md.push_str(&format!(
            "**Date**: {} | **Endpoint**: {} | **Concurrency**: {}\n\n",
            self.timestamp, self.endpoint, self.max_concurrent,
        ));

        md.push_str("## Summary\n\n");
        md.push_str("| Metric | Value |\n|--------|-------|\n");
        md.push_str(&format!(
            "| Tasks | {}/{} passed ({:.0}% error rate) |\n",
            self.tasks_passed,
            self.tasks_total,
            self.error_rate * 100.0,
        ));
        md.push_str(&format!("| Avg Score | {:.1}% |\n", self.avg_score * 100.0,));
        md.push_str(&format!(
            "| Throughput | {:.0} tok/s |\n",
            self.tokens_per_sec,
        ));
        md.push_str(&format!(
            "| Tokens | {} prompt + {} completion |\n",
            format_tokens(self.total_prompt_tokens),
            format_tokens(self.total_completion_tokens),
        ));
        md.push_str(&format!(
            "| Duration | {:.1}s |\n",
            self.total_duration_secs,
        ));

        md.push_str("\n## Latency\n\n");
        md.push_str("| Percentile | ms |\n|-----------|----|\n");
        md.push_str(&format!("| p50 | {} |\n", self.latency_p50_ms));
        md.push_str(&format!("| p95 | {} |\n", self.latency_p95_ms));
        md.push_str(&format!("| p99 | {} |\n", self.latency_p99_ms));
        md.push_str(&format!("| avg | {:.0} |\n", self.latency_avg_ms));
        md.push_str(&format!(
            "| min/max | {}/{} |\n",
            self.latency_min_ms, self.latency_max_ms,
        ));

        md.push_str("\n## Per-Task Results\n\n");
        md.push_str("| Task | Status | Score | Latency | Tokens |\n");
        md.push_str("|------|--------|-------|---------|--------|\n");
        for r in &self.results {
            let status = if r.success { "PASS" } else { "FAIL" };
            let score = r
                .eval
                .as_ref()
                .map(|e| format!("{:.0}%", e.score * 100.0))
                .unwrap_or_else(|| "N/A".into());
            md.push_str(&format!(
                "| {} | {} | {} | {}ms | {}+{} |\n",
                r.task_id, status, score, r.latency_ms, r.prompt_tokens, r.completion_tokens,
            ));
        }

        md
    }

    /// Write report files to the output directory.
    pub fn write_to_dir(&self, dir: &std::path::Path) -> anyhow::Result<()> {
        std::fs::create_dir_all(dir)?;
        std::fs::write(dir.join("bench_report.json"), self.to_json()?)?;
        std::fs::write(dir.join("bench_report.md"), self.to_markdown())?;
        Ok(())
    }
}

/// Calculate the nth percentile from a sorted slice.
fn percentile(sorted: &[u64], pct: usize) -> u64 {
    if sorted.is_empty() {
        return 0;
    }
    let idx = (pct as f64 / 100.0 * (sorted.len() - 1) as f64).round() as usize;
    sorted[idx.min(sorted.len() - 1)]
}

/// Format a token count with thousand separators.
fn format_tokens(n: u64) -> String {
    let s = n.to_string();
    let mut result = String::new();
    for (i, ch) in s.chars().rev().enumerate() {
        if i > 0 && i % 3 == 0 {
            result.push(',');
        }
        result.push(ch);
    }
    result.chars().rev().collect()
}

#[cfg(test)]
#[path = "../../tests/unit/bench_harness/report/report_test.rs"]
mod tests;