import type { ResumePlan } from "../shared/types";
import { formatRange, type Corpus } from "./db";

/** Escape dynamic text for pdflatex (inputenc utf8 + fontenc T1, Computer Modern). */
export function escapeLatex(s: string): string {
  let t = s.replace(/\\/g, "\u0000");
  t = t.replace(/([&%$#_{}])/g, "\\$1");
  t = t.replace(/~/g, "\\textasciitilde{}").replace(/\^/g, "\\textasciicircum{}");
  t = t.replace(/\u0000/g, "\\textbackslash{}");
  t = t
    .replace(/[\u2018\u2019\u02bc]/g, "'")
    .replace(/\u201c/g, "``")
    .replace(/\u201d/g, "''")
    .replace(/"([^"]*)"/g, "``$1''")
    .replace(/"/g, "''")
    .replace(/\u2014/g, "---")
    .replace(/[\u2012\u2013]/g, "--")
    .replace(/[\u2010\u2011\u2212]/g, "-")
    .replace(/\u00b7/g, "\\textperiodcentered{}")
    .replace(/[\u2022\u25aa\u25cf]/g, "\\textbullet{}")
    .replace(/\u2026/g, "\\ldots{}")
    .replace(/[\u00a0\u2007\u202f]/g, "~");
  return t.replace(/[^\x20-\x7e]/g, "");
}

function itemize(bullets: string[]): string {
  const items = bullets.map((b) => `  \\item \\small{${escapeLatex(b)}}`).join("\n");
  return `\\begin{itemize}[leftmargin=*, nosep, topsep=2pt]\n${items}\n\\end{itemize}`;
}

/**
 * Fill the shared résumé template (same preamble and layout as ../src/*.tex)
 * with a tailored plan plus the role-independent corpus blocks.
 */
export function renderLatex(corpus: Corpus, plan: ResumePlan): string {
  const p = corpus.profile;

  const contact: string[] = [];
  if (p.email) contact.push(`\\href{mailto:${p.email}}{${escapeLatex(p.email)}}`);
  if (p.phone) contact.push(escapeLatex(p.phone));
  if (p.website) contact.push(`\\href{${p.website}}{Website}`);
  if (p.linkedin) contact.push(`\\href{${p.linkedin}}{LinkedIn}`);
  if (p.github) contact.push(`\\href{${p.github}}{GitHub}`);
  if (p.twitter) contact.push(`\\href{${p.twitter}}{Twitter}`);

  const skillGroups = plan.skills
    .map((g) => `\\textbf{${escapeLatex(g.group)}}\\\\[1pt]\n${escapeLatex(g.items.join(", "))}\\\\[5pt]`)
    .join("\n");

  const honors = corpus.honors
    .map(
      (h) =>
        `\\textbf{${escapeLatex(h.title)}}\\\\[1pt]\n${escapeLatex(h.institution ?? "")} \\hfill \\textit{${h.date?.slice(0, 4) ?? ""}}\\\\[4pt]`,
    )
    .join("\n");

  const organizations = corpus.organizations
    .map((o) => `\\textbf{${escapeLatex(o.name)}}\\\\[1pt]\n${escapeLatex(o.title ?? "")}\\\\[4pt]`)
    .join("\n");

  const experience = plan.experience
    .flatMap((sel) => {
      const row = corpus.experience.find((e) => e.slug === sel.slug);
      if (!row || sel.bullets.length === 0) return [];
      const dates = escapeLatex(formatRange(row.start_date, row.end_date, "month"));
      const where = row.location ? `${escapeLatex(row.company)} --- ${escapeLatex(row.location)}` : escapeLatex(row.company);
      return [
        `\\textbf{${escapeLatex(row.title)}} \\hfill \\textit{${dates}}\\\\\n\\textit{${where}}\n${itemize(sel.bullets)}\n\\vspace{6pt}`,
      ];
    })
    .join("\n");

  const projects = plan.projects
    .flatMap((sel) => {
      const row = corpus.projects.find((pr) => pr.slug === sel.slug);
      if (!row || sel.bullets.length === 0) return [];
      const dates = escapeLatex(formatRange(row.start_date, row.end_date, "year"));
      return [`\\textbf{${escapeLatex(sel.heading)}} \\hfill \\textit{${dates}}\n${itemize(sel.bullets)}\n\\vspace{4pt}`];
    })
    .join("\n");

  const edu = corpus.education;
  const education = edu
    ? `\\textbf{B.S. in ${escapeLatex(edu.field ?? "")}} \\hfill \\textit{${escapeLatex(formatRange(edu.start_date, edu.end_date, "year"))}}\\\\\n\\textit{${escapeLatex(edu.school)}}`
    : "";

  return `\\documentclass[11pt]{article}
\\usepackage[utf8]{inputenc}
\\usepackage[T1]{fontenc}
\\usepackage{geometry}
\\usepackage{enumitem}
\\usepackage{paracol}
\\usepackage[hidelinks]{hyperref}
\\geometry{a4paper, margin=0.5in}
\\setlength{\\parindent}{0pt}
\\setlength{\\parskip}{2pt}
\\columnratio{0.3}

\\begin{document}

{\\centering
  {\\Huge \\textbf{${escapeLatex(p.full_name)}}}\\\\[2pt]
  {\\large ${escapeLatex(plan.title)}}
  \\par
}
\\vspace{14pt}

\\begin{paracol}{2}
\\raggedright
\\small
{\\bfseries Contact}\\\\[2pt]
\\rule{\\linewidth}{0.4pt}\\\\[4pt]
${contact.join("\\\\[2pt]\n")}

\\vspace{8pt}

{\\bfseries Skills}\\\\[2pt]
\\rule{\\linewidth}{0.4pt}\\\\[4pt]
${skillGroups}

\\vspace{8pt}

{\\bfseries Honors}\\\\[2pt]
\\rule{\\linewidth}{0.4pt}\\\\[4pt]
${honors}

\\vspace{8pt}

{\\bfseries Organizations}\\\\[2pt]
\\rule{\\linewidth}{0.4pt}\\\\[4pt]
${organizations}

\\switchcolumn
\\normalsize
\\raggedright
{\\bfseries Experience}\\\\[2pt]
\\rule{\\linewidth}{0.4pt}\\\\[4pt]
${experience}

{\\bfseries Projects}\\\\[2pt]
\\rule{\\linewidth}{0.4pt}\\\\[4pt]
${projects}

{\\bfseries Education}\\\\[2pt]
\\rule{\\linewidth}{0.4pt}\\\\[4pt]
${education}
\\vspace{4pt}

\\end{paracol}

\\end{document}
`;
}