import type { AgentRunLog } from "@/lib/agent-run-log-types";

/** Markdown export for pasting into an LLM — safe for client bundles (no Redis). */
export function buildDebugTrace(run: AgentRunLog): string {
  const lines: string[] = [];
  const ts = new Date(run.startedAt).toISOString();

  lines.push("# Job Scorer Agent Debug Trace");
  lines.push(`Run ID: \`${run.runId}\``);
  lines.push(`User: \`${run.userId}\``);
  if (run.sessionId) lines.push(`Session: \`${run.sessionId}\``);
  lines.push(`Started: ${ts}`);
  lines.push(`Duration: ${(run.durationMs / 1000).toFixed(1)}s`);
  lines.push(`Stopped because: **${run.stoppedBecause}**`);
  lines.push(`Credit cost: ${run.creditCost}`);
  lines.push(`Result: ${run.finalResultSummary ?? "none"}`);
  if (run.errorMessage) lines.push(`Run error: ${run.errorMessage}`);
  lines.push("");

  lines.push("## Completion Steps (LLM decisions)");
  for (const step of run.completionSteps) {
    lines.push(`### Step ${step.stepIndex + 1} — ${step.model || "?"} (${step.provider})`);
    lines.push(`Duration: ${step.durationMs}ms`);

    if (step.assistantReasoningText) {
      lines.push("**Model reasoning before tool call:**");
      lines.push(`> ${step.assistantReasoningText.replace(/\n/g, "\n> ")}`);
    }

    if (step.toolCalls?.length) {
      lines.push("**Tool calls chosen:**");
      for (const tc of step.toolCalls) {
        lines.push(`- \`${tc.name}\`: \`${JSON.stringify(tc.input).slice(0, 200)}\``);
      }
    } else if (!step.errorMessage) {
      lines.push("*No tool call — final response turn*");
    }

    if (step.errorMessage) {
      lines.push(`**Error:** ${step.errorMessage}`);
    }

    if (step.messages?.length) {
      lines.push(`<details><summary>Full message array (${step.messages.length} messages)</summary>`);
      lines.push("");
      lines.push("```json");
      lines.push(JSON.stringify(step.messages, null, 2).slice(0, 8000));
      lines.push("```");
      lines.push("</details>");
    }
    lines.push("");
  }

  lines.push("## Tool Timeline");
  for (const t of run.tools) {
    const status = t.status === "ok" ? "✓" : t.status === "error" ? "✗" : "⚠";
    lines.push(`${status} **${t.tool}** — ${t.durationMs}ms — ${t.provider ?? "unknown provider"}`);
    if (t.resultSummary) lines.push(`  Result: ${t.resultSummary}`);
    if (t.creditCost !== undefined && t.creditCost > 0) lines.push(`  Credits: ${t.creditCost}`);
    if (t.input && Object.keys(t.input).length > 0) {
      lines.push(`  Input: \`${JSON.stringify(t.input).slice(0, 300)}\``);
    }
  }

  lines.push("");
  lines.push("---");
  lines.push("*Job Scorer debug trace — paste into Claude for diagnosis*");
  return lines.join("\n");
}