/**
 * Generates README.md with Mermaid org chart for company exports.
 */
import type { CompanyPortabilityManifest } from "@paperclipai/shared";

const ROLE_LABELS: Record<string, string> = {
  ceo: "CEO",
  cto: "CTO",
  cmo: "CMO",
  cfo: "CFO",
  coo: "COO",
  vp: "VP",
  manager: "Manager",
  engineer: "Engineer",
  agent: "Agent",
};

/**
 * Generate a Mermaid flowchart (TD = top-down) representing the org chart.
 * Returns null if there are no agents.
 */
export function generateOrgChartMermaid(agents: CompanyPortabilityManifest["agents"]): string | null {
  if (agents.length === 0) return null;

  const lines: string[] = [];
  lines.push("```mermaid");
  lines.push("graph TD");

  // Node definitions with role labels
  for (const agent of agents) {
    const roleLabel = ROLE_LABELS[agent.role] ?? agent.role;
    const id = mermaidId(agent.slug);
    lines.push(`    ${id}["${mermaidEscape(agent.name)}<br/><small>${mermaidEscape(roleLabel)}</small>"]`);
  }

  // Edges from parent to child
  const slugSet = new Set(agents.map((a) => a.slug));
  for (const agent of agents) {
    if (agent.reportsToSlug && slugSet.has(agent.reportsToSlug)) {
      lines.push(`    ${mermaidId(agent.reportsToSlug)} --> ${mermaidId(agent.slug)}`);
    }
  }

  lines.push("```");
  return lines.join("\n");
}

/** Sanitize slug for use as a Mermaid node ID (alphanumeric + underscore). */
function mermaidId(slug: string): string {
  return slug.replace(/[^a-zA-Z0-9_]/g, "_");
}

/** Escape text for Mermaid node labels. */
function mermaidEscape(s: string): string {
  return s.replace(/"/g, "&quot;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
}

/**
 * Generate the README.md content for a company export.
 */
export function generateReadme(
  manifest: CompanyPortabilityManifest,
  options: {
    companyName: string;
    companyDescription: string | null;
  },
): string {
  const lines: string[] = [];

  lines.push(`# ${options.companyName}`);
  lines.push("");
  if (options.companyDescription) {
    lines.push(`> ${options.companyDescription}`);
    lines.push("");
  }

  // Org chart as Mermaid diagram
  const mermaid = generateOrgChartMermaid(manifest.agents);
  if (mermaid) {
    lines.push(mermaid);
    lines.push("");
  }

  // What's Inside table
  lines.push("## What's Inside");
  lines.push("");
  lines.push("This is an [Agent Company](https://paperclip.ing) package.");
  lines.push("");

  const counts: Array<[string, number]> = [];
  if (manifest.agents.length > 0) counts.push(["Agents", manifest.agents.length]);
  if (manifest.projects.length > 0) counts.push(["Projects", manifest.projects.length]);
  if (manifest.skills.length > 0) counts.push(["Skills", manifest.skills.length]);
  if (manifest.issues.length > 0) counts.push(["Tasks", manifest.issues.length]);

  if (counts.length > 0) {
    lines.push("| Content | Count |");
    lines.push("|---------|-------|");
    for (const [label, count] of counts) {
      lines.push(`| ${label} | ${count} |`);
    }
    lines.push("");
  }

  // Agents table
  if (manifest.agents.length > 0) {
    lines.push("### Agents");
    lines.push("");
    lines.push("| Agent | Role | Reports To |");
    lines.push("|-------|------|------------|");
    for (const agent of manifest.agents) {
      const roleLabel = ROLE_LABELS[agent.role] ?? agent.role;
      const reportsTo = agent.reportsToSlug ?? "\u2014";
      lines.push(`| ${agent.name} | ${roleLabel} | ${reportsTo} |`);
    }
    lines.push("");
  }

  // Projects list
  if (manifest.projects.length > 0) {
    lines.push("### Projects");
    lines.push("");
    for (const project of manifest.projects) {
      const desc = project.description ? ` \u2014 ${project.description}` : "";
      lines.push(`- **${project.name}**${desc}`);
    }
    lines.push("");
  }

  // Getting Started
  lines.push("## Getting Started");
  lines.push("");
  lines.push("```bash");
  lines.push("pnpm paperclipai company import this-github-url-or-folder");
  lines.push("```");
  lines.push("");
  lines.push("See [Paperclip](https://paperclip.ing) for more information.");
  lines.push("");

  // Footer
  lines.push("---");
  lines.push(`Exported from [Paperclip](https://paperclip.ing) on ${new Date().toISOString().split("T")[0]}`);
  lines.push("");

  return lines.join("\n");
}