"""Prometheus text exposition: aggregates only (R-VULN-06). The label allowlist is state, severity, fixable."""
from datetime import timedelta

import report as report_mod
from state import parse_ts

_CRITICAL_GRACE = timedelta(hours=72)
_SEVERITIES = ("CRITICAL", "HIGH", "MEDIUM", "LOW", "UNKNOWN")


def _sample(lines, name, value, labels=""):
    lines.append(name + labels + " " + format(value, ".0f" if float(value).is_integer() else "g"))


def render(report, state, now):
    lines = []
    if report is not None:
        _sample(lines, "vuln_scanner_report_generated_timestamp_seconds", parse_ts(report["generatedAt"]).timestamp())
        _sample(lines, "vuln_scanner_database_updated_timestamp_seconds", parse_ts(report["database"]["updatedAt"]).timestamp())
        counts = {name: 0 for name in report_mod.STATES}
        for target in report["targets"]:
            counts[target["state"]] += 1
        for name in report_mod.STATES:
            _sample(lines, "vuln_scanner_targets", counts[name], '{state="' + name + '"}')
        findings = {(sev, fix): 0 for sev in _SEVERITIES for fix in ("true", "false")}
        overdue = 0
        for finding in report["findings"]:
            if finding["status"] == "accepted":
                continue
            findings[(finding["severity"], "true" if finding["fixedVersion"] else "false")] += 1
            if finding["severity"] == "CRITICAL" and finding["fixedVersion"]:
                first_seen = parse_ts(finding["firstSeenAt"])
                if first_seen and now - first_seen > _CRITICAL_GRACE:
                    overdue += 1
        for (severity, fixable), value in sorted(findings.items()):
            _sample(lines, "vuln_scanner_findings", value, '{severity="' + severity + '",fixable="' + fixable + '"}')
        _sample(lines, "vuln_scanner_critical_fix_overdue", overdue)
    _sample(lines, "vuln_scanner_failed_targets_over_24h", report_mod.failed_over_24h(state, now))
    for name, key in (("vuln_scanner_last_complete_run_timestamp_seconds", "lastCompleteRunAt"),
                      ("vuln_scanner_triage_heartbeat_timestamp_seconds", "triageHeartbeatAt")):
        value = parse_ts(state.get(key))
        if value is not None:
            _sample(lines, name, value.timestamp())
    return "\n".join(lines) + "\n"