"use node";

import { api, internal } from "./_generated/api";
import { internalAction } from "./_generated/server";
import type { Id } from "./_generated/dataModel";
import type { ActionCtx } from "./_generated/server";
import { v } from "convex/values";
import {
  classifyPageSpeedError,
  fetchPageSpeedResult,
  normalizePageSpeedResult,
  type PageSpeedErrorType,
} from "../lib/pagespeed-insights";

const STRATEGIES = ["mobile", "desktop"] as const;
export const MAX_RAW_PAGESPEED_BYTES = 1_000_000;
const RAW_PAGESPEED_BYTES_SUMMARY =
  "PageSpeed-Rohdaten sind groesser als das interne Speicherlimit.";
const DEFAULT_PAGESPEED_TIMEOUT_MS = 60_000;
const MIN_PAGESPEED_TIMEOUT_MS = 10_000;
const MAX_PAGESPEED_TIMEOUT_MS = 120_000;

function toPersistedPageSpeedNormalizedResult(
  normalized: ReturnType<typeof normalizePageSpeedResult>,
) {
  return {
    ...(normalized.scores ? { scores: normalized.scores } : {}),
    metrics: normalized.metrics,
    opportunities: normalized.opportunities,
    implications: normalized.implications,
  };
}

function parsePageSpeedTimeoutMs(raw: string | undefined): number {
  if (!raw) {
    return DEFAULT_PAGESPEED_TIMEOUT_MS;
  }

  const parsed = Number.parseInt(raw, 10);
  if (!Number.isFinite(parsed)) {
    return DEFAULT_PAGESPEED_TIMEOUT_MS;
  }

  return Math.min(
    Math.max(parsed, MIN_PAGESPEED_TIMEOUT_MS),
    MAX_PAGESPEED_TIMEOUT_MS,
  );
}

function resolvePageSpeedTimeoutMs() {
  return parsePageSpeedTimeoutMs(process.env.PAGESPEED_TIMEOUT_MS);
}

function isPageSpeedErrorType(value: unknown): value is PageSpeedErrorType {
  return (
    value === "quota" ||
    value === "timeout" ||
    value === "unavailable" ||
    value === "invalid_url" ||
    value === "api_error" ||
    value === "unknown"
  );
}

function sanitizeValue(value: string, secret?: string | null) {
  if (!secret || !value) {
    return value;
  }
  const escapedSecret = secret.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
  return value.replace(new RegExp(escapedSecret, "g"), "[REDACTED]");
}

function classifyPageSpeedFailure(input: unknown, apiKey?: string | null) {
  const directType =
    typeof input === "object" &&
    input !== null &&
    "errorType" in input &&
    (input as { errorType?: unknown }).errorType;

  const normalizedType = isPageSpeedErrorType(directType) ? directType : null;
  if (normalizedType) {
    const message =
      input instanceof Error && input.message
        ? input.message
        : typeof input === "string"
          ? input
          : "PageSpeed-Analyse fehlgeschlagen.";
    return {
      errorType: normalizedType,
      errorSummary: sanitizeValue(message, apiKey),
    };
  }

  const classified = classifyPageSpeedError({
    error: input,
  });
  const errorSummary = sanitizeValue(classified.message, apiKey);

  return {
    errorType: classified.errorType,
    errorSummary,
  };
}

type StartedPageSpeedAudit = {
  lead: {
    _id: Id<"leads">;
    websiteUrl: string;
  };
  auditId?: Id<"audits">;
};

async function queueAuditGenerationAfterPageSpeed(
  ctx: ActionCtx,
  runId: Id<"agentRuns">,
  started: StartedPageSpeedAudit,
) {
  try {
    await ctx.runMutation(internal.auditGeneration.queueLeadAuditGeneration, {
      leadId: started.lead._id,
      ...(started.auditId ? { auditId: started.auditId } : {}),
      parentRunId: runId,
    });
  } catch (auditQueueError) {
    await ctx.runMutation(api.runs.appendEvent, {
      runId,
      level: "warning",
      message: "Audit-Generierung konnte nicht in die Warteschlange gesetzt werden.",
      details: [
        { label: "Lead", value: started.lead._id },
        {
          label: "Fehler",
          value: auditQueueError instanceof Error
            ? auditQueueError.message
            : String(auditQueueError),
          source: "audit_generation_queue",
        },
      ],
    });
  }
}

export const processPageSpeedAudit = internalAction({
  args: {
    runId: v.id("agentRuns"),
  },
  handler: async (ctx, args) => {
    const apiKeyRaw = process.env.PAGESPEED_API_KEY?.trim();
    const apiKey = apiKeyRaw ? apiKeyRaw : undefined;

    let started: StartedPageSpeedAudit | null = null;

    try {
      started = await ctx.runMutation(internal.pageSpeed.startPageSpeedAuditRun, {
        runId: args.runId,
      });
    } catch (error) {
      const { errorSummary } = classifyPageSpeedFailure(error, apiKeyRaw);

      await ctx.runMutation(internal.pageSpeed.finishPageSpeedAuditRun, {
        runId: args.runId,
        status: "failed",
        errors: 1,
        errorSummary,
      });

      await ctx.runMutation(api.runs.appendEvent, {
        runId: args.runId,
        level: "error",
        message: "PageSpeed-Analyse fehlgeschlagen.",
        details: [{ label: "Fehler", value: errorSummary }],
      });

      return null;
    }

    if (!started) {
      return null;
    }

    const sourceUrl = started.lead.websiteUrl;
    const timeoutMs = resolvePageSpeedTimeoutMs();

    let failedStrategies = 0;
    let succeededStrategies = 0;

    try {
      for (const strategy of STRATEGIES) {
        const fetchedAt = Date.now();
        try {
          const raw = await fetchPageSpeedResult({
            url: sourceUrl,
            strategy,
            apiKey,
            timeoutMs,
          });
          const rawJson = JSON.stringify(raw) ?? "null";
          const rawJsonBytes = new TextEncoder().encode(rawJson).byteLength;
          if (rawJsonBytes > MAX_RAW_PAGESPEED_BYTES) {
            failedStrategies += 1;
            await ctx.runMutation(internal.pageSpeed.persistPageSpeedResult, {
              leadId: started.lead._id,
              ...(started.auditId ? { auditId: started.auditId } : {}),
              runId: args.runId,
              strategy,
              status: "failed",
              sourceUrl,
              errorType: "api_error",
              errorSummary: RAW_PAGESPEED_BYTES_SUMMARY,
              fetchedAt,
            });

            await ctx.runMutation(api.runs.appendEvent, {
              runId: args.runId,
              level: "warning",
              message: `PageSpeed-Analyse für ${strategy} fehlgeschlagen.`,
              details: [
                { label: "Strategie", value: strategy },
                {
                  label: "Fehler",
                  value: RAW_PAGESPEED_BYTES_SUMMARY,
                },
              ],
            });

            continue;
          }

          const rawStorageId = await ctx.storage.store(
            new Blob([rawJson], { type: "application/json" }),
          );
          const normalized = normalizePageSpeedResult({
            strategy,
            sourceUrl,
            raw,
          });

          await ctx.runMutation(internal.pageSpeed.persistPageSpeedResult, {
            leadId: started.lead._id,
            ...(started.auditId ? { auditId: started.auditId } : {}),
            runId: args.runId,
            strategy,
            status: "succeeded",
            sourceUrl,
            finalUrl: normalized.finalUrl,
            rawStorageId,
            fetchedAt,
            normalized: toPersistedPageSpeedNormalizedResult(normalized),
          });

          await ctx.runMutation(api.runs.appendEvent, {
            runId: args.runId,
            level: "info",
            message: `PageSpeed-Analyse für ${strategy} abgeschlossen.`,
            details: [{ label: "Strategie", value: strategy }],
          });
          succeededStrategies += 1;
        } catch (error) {
          const { errorType, errorSummary } = classifyPageSpeedFailure(
            error,
            apiKeyRaw,
          );
          failedStrategies += 1;

          await ctx.runMutation(internal.pageSpeed.persistPageSpeedResult, {
            leadId: started.lead._id,
            ...(started.auditId ? { auditId: started.auditId } : {}),
            runId: args.runId,
            strategy,
            status: "failed",
            sourceUrl,
            errorType,
            errorSummary,
            fetchedAt,
          });

          await ctx.runMutation(api.runs.appendEvent, {
            runId: args.runId,
            level: "warning",
            message: `PageSpeed-Analyse für ${strategy} fehlgeschlagen.`,
            details: [
              { label: "Strategie", value: strategy },
              { label: "Fehler", value: errorSummary },
            ],
          });
        }
      }

      const status = succeededStrategies > 0 ? "succeeded" : "failed";
      const errors = failedStrategies;
      await ctx.runMutation(internal.pageSpeed.finishPageSpeedAuditRun, {
        runId: args.runId,
        status,
        errors,
        errorSummary:
          status === "failed" && errors > 0
            ? "Ein oder mehrere PageSpeed-Strategien konnten nicht ausgeführt werden."
            : undefined,
      });

      await queueAuditGenerationAfterPageSpeed(ctx, args.runId, started);

      return args.runId;
    } catch (error) {
      const { errorSummary } = classifyPageSpeedFailure(error, apiKeyRaw);
      await ctx.runMutation(internal.pageSpeed.finishPageSpeedAuditRun, {
        runId: args.runId,
        status: "failed",
        errors: Math.max(1, failedStrategies),
        errorSummary,
      });

      await ctx.runMutation(api.runs.appendEvent, {
        runId: args.runId,
        level: "error",
        message: "PageSpeed-Analyse fehlgeschlagen.",
        details: [{ label: "Fehler", value: errorSummary, source: "pagespeed_action" }],
      });
      await queueAuditGenerationAfterPageSpeed(ctx, args.runId, started);
      return null;
    }
  },
});