/**
 * @module mcp-server/tools/traffic
 * MCP Tool: IX traffic statistics and port utilization.
 *
 * Provides IX-level traffic data, trend analysis, and port utilization
 * monitoring using public IX statistics APIs.
 */

import { z } from "zod";

// ── Tool Schemas ─────────────────────────────────────────

/** Input schema for IX traffic query */
export const ixTrafficSchema = z.object({
  ix: z
    .string()
    .describe("IX name or identifier (e.g., 'de-cix-frankfurt', 'ams-ix', 'linx-lon1')"),
  period: z
    .string()
    .optional()
    .default("30d")
    .describe("Time period (e.g., '7d', '30d', '12m', '1y')"),
  granularity: z
    .enum(["5min", "hourly", "daily", "weekly", "monthly"])
    .optional()
    .default("daily")
    .describe("Data point granularity (default: daily)"),
});

/** Input schema for IX comparison */
export const ixComparisonSchema = z.object({
  ixes: z
    .array(z.string())
    .min(2)
    .max(10)
    .describe("Array of IX identifiers to compare (min 2, max 10)"),
  period: z
    .string()
    .optional()
    .default("30d")
    .describe("Time period for comparison"),
});

/** Input schema for port utilization */
export const portUtilizationSchema = z.object({
  asn: z
    .union([z.string(), z.number()])
    .describe("ASN to check port utilization for"),
  ix: z
    .string()
    .optional()
    .describe("Specific IX to check (default: all connected IXes)"),
});

// ── Result Types ─────────────────────────────────────────

/** Traffic trend data point */
export interface TrafficTrend {
  readonly timestamp: string;
  readonly peakBps: number;
  readonly avgBps: number;
  readonly p95Bps: number;
}

/** IX traffic report */
export interface IXTrafficReport {
  readonly ix: string;
  readonly displayName: string;
  readonly period: string;
  readonly currentStats: {
    readonly peakBps: number;
    readonly avgBps: number;
    readonly connectedNetworks: number;
    readonly totalPorts: number;
    readonly totalCapacityBps: number;
  };
  readonly trends: ReadonlyArray<TrafficTrend>;
  readonly growth: {
    readonly peakGrowthPercent: number;
    readonly avgGrowthPercent: number;
    readonly networkGrowthPercent: number;
  };
  readonly fetchedAt: string;
}

/** IX comparison result */
export interface IXComparisonReport {
  readonly ixes: ReadonlyArray<{
    readonly ix: string;
    readonly displayName: string;
    readonly peakTbps: number;
    readonly avgTbps: number;
    readonly networks: number;
    readonly growthPercent: number;
  }>;
  readonly period: string;
  readonly largestByPeak: string;
  readonly fastestGrowing: string;
}

/** Port utilization report */
export interface PortUtilizationReport {
  readonly asn: number;
  readonly name: string;
  readonly ixPorts: ReadonlyArray<{
    readonly ix: string;
    readonly portSpeedGbps: number;
    readonly avgUtilizationPercent: number;
    readonly peakUtilizationPercent: number;
    readonly recommendation: string;
  }>;
  readonly overallRecommendation: string;
}

// ── Tool Handlers ────────────────────────────────────────

/**
 * Get traffic statistics and trends for an Internet Exchange.
 *
 * @param input - Validated traffic query parameters
 * @returns Traffic report with historical trends
 *
 * @example
 * ```
 * > Show IX traffic trends at DE-CIX Frankfurt for the last 12 months
 *
 * Returns: Current peak/avg traffic, monthly trends, growth rates,
 * and network count over time.
 * ```
 */
export async function handleIXTraffic(
  input: z.infer<typeof ixTrafficSchema>
): Promise<IXTrafficReport> {
  // TODO: Query IX traffic client for stats
  // TODO: Parse period string and calculate date range
  // TODO: Aggregate data points to requested granularity
  // TODO: Calculate growth metrics

  return {
    ix: input.ix,
    displayName: input.ix.replace(/-/g, " ").toUpperCase(),
    period: input.period ?? "30d",
    currentStats: {
      peakBps: 0,
      avgBps: 0,
      connectedNetworks: 0,
      totalPorts: 0,
      totalCapacityBps: 0,
    },
    trends: [],
    growth: {
      peakGrowthPercent: 0,
      avgGrowthPercent: 0,
      networkGrowthPercent: 0,
    },
    fetchedAt: new Date().toISOString(),
  };
}

/**
 * Compare traffic statistics across multiple IXes.
 *
 * @param input - Validated comparison parameters
 * @returns Side-by-side IX comparison
 *
 * @example
 * ```
 * > Compare DE-CIX Frankfurt, AMS-IX, and LINX traffic
 *
 * Returns: Peak/avg traffic, network count, and growth for each IX.
 * ```
 */
export async function handleIXComparison(
  input: z.infer<typeof ixComparisonSchema>
): Promise<IXComparisonReport> {
  // TODO: Fetch traffic for each IX in parallel
  // TODO: Normalize units and time periods
  // TODO: Rank by peak, average, and growth

  return {
    ixes: input.ixes.map((ix) => ({
      ix,
      displayName: ix.replace(/-/g, " ").toUpperCase(),
      peakTbps: 0,
      avgTbps: 0,
      networks: 0,
      growthPercent: 0,
    })),
    period: input.period ?? "30d",
    largestByPeak: input.ixes[0],
    fastestGrowing: input.ixes[0],
  };
}

/**
 * Analyze port utilization for an ASN across its IX connections.
 *
 * @param input - Validated utilization parameters
 * @returns Port utilization report with upgrade recommendations
 *
 * @example
 * ```
 * > Is AS13335 (Cloudflare) oversubscribed at any IX?
 *
 * Returns: Port speeds, utilization percentages, and upgrade recommendations
 * for each IX connection.
 * ```
 */
export async function handlePortUtilization(
  input: z.infer<typeof portUtilizationSchema>
): Promise<PortUtilizationReport> {
  // TODO: Query PeeringDB for IX port speeds
  // TODO: Cross-reference with IX traffic data if available
  // TODO: Generate utilization estimates and recommendations

  const _input = input;

  return {
    asn: 0, // TODO: parseASN(input.asn)
    name: "",
    ixPorts: [],
    overallRecommendation:
      "Insufficient data — port utilization requires IX-specific telemetry access.",
  };
}
