#!/usr/bin/env python3
"""Generate role-tailored LaTeX CVs from documents/sources/ YAML.

Layout matches the two-column paracol examples in documents/cv/
(PradNukala_StaffSoftwareEngineer_Circle.tex et al.). Everything factual
is pulled from documents/sources/:

- Contact block           <- about/profile.yml
- Honors / Organizations  <- about/honors.yml, about/organizations.yml
- Education               <- about/education.yml
- Experience entries      <- experience/<name>.yml (title, company, dates,
                             location, and description bullets)
- Project entries         <- projects/<name>.yml (title, dates, bullets)
- Skills                  <- skills/*.yml (whole groups via `from:`, or
                             explicit items validated against the sources)

A role config (documents/cv/roles/<role>.yml) selects and arranges that
material. Experience/project bullets are either `use: N` (1-based index
into the source's description bullets, verbatim) or a literal string (a
condensed rewrite; must stay grounded in the same source).

Usage:
    python3 tools/generate_cv.py --list
    python3 tools/generate_cv.py staff-software-engineer
    python3 tools/generate_cv.py --all
    python3 tools/generate_cv.py <role> --output cv/custom_name.tex

Dates are emitted with a single ASCII hyphen ("Mar 2021 - Present"), not
"--": LaTeX ligatures "--" into an en-dash that breaks ATS date-range
parsing (see 05-cv-templates.md, "Date fields must be ASCII ranges").
"""

import argparse
import sys
from pathlib import Path

import yaml

REPO = Path(__file__).resolve().parent.parent
SOURCES = REPO / "documents" / "sources"
ROLES_DIR = REPO / "documents" / "cv" / "roles"
OUT_DIR = REPO / "cv"

MONTHS = [
    "Jan", "Feb", "Mar", "Apr", "May", "Jun",
    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
]

# Multi-char substitutions applied before single-char escaping.
_UNICODE_SUBS = [
    ("\u2014", "---"),   # em dash
    ("\u2013", "--"),    # en dash
    ("\u201c", "``"),    # left double quote
    ("\u201d", "''"),    # right double quote
    ("\u2018", "`"),     # left single quote
    ("\u2019", "'"),     # right single quote
    ("\u2026", "\\ldots{}"),
    ("\u00b7", "\\textperiodcentered{}"),
    ("\u0113", "\\=e"),  # ē (Yuē) - not in T1-encoded fonts
]

_CHAR_ESCAPES = {
    "&": "\\&",
    "%": "\\%",
    "$": "\\$",
    "#": "\\#",
    "_": "\\_",
    "~": "\\textasciitilde{}",
    "^": "\\textasciicircum{}",
}


class ConfigError(Exception):
    """Raised when a role config or source file is unusable."""


def latex_escape(text):
    """Escape plain text (from YAML) for use in LaTeX body text."""
    text = str(text).strip()
    for src, dst in _UNICODE_SUBS:
        text = text.replace(src, dst)
    return "".join(_CHAR_ESCAPES.get(ch, ch) for ch in text)


def load_yaml(path):
    try:
        with open(path, encoding="utf-8") as handle:
            return yaml.safe_load(handle)
    except FileNotFoundError as exc:
        raise ConfigError(f"missing source file: {path}") from exc
    except yaml.YAMLError as exc:
        raise ConfigError(f"invalid YAML in {path}: {exc}") from exc


def parse_bullets(description):
    """Split a description block scalar into individual bullets.

    Lines starting with "- " open a new bullet; other non-blank lines
    continue the current one. Leading prose before the first "- " (see
    projects/ecosystem-devrel.yml) becomes its own bullet.
    """
    bullets = []
    current = []
    for line in (description or "").splitlines():
        stripped = line.strip()
        if not stripped:
            continue
        if stripped.startswith("- "):
            if current:
                bullets.append(" ".join(current))
            current = [stripped[2:].strip()]
        else:
            current.append(stripped)
    if current:
        bullets.append(" ".join(current))
    return bullets


def format_month_year(value):
    return f"{MONTHS[value.month - 1]} {value.year}"


def format_range(start, end, month=True):
    """Render a date range with an ASCII hyphen (ATS-parseable)."""
    fmt = format_month_year if month else (lambda d: str(d.year))
    left = fmt(start) if hasattr(start, "year") else str(start)
    right = "Present" if end is None else (fmt(end) if hasattr(end, "year") else str(end))
    return f"{left} - {right}"


def _skill_aliases(name):
    """Known spellings for one canonical skill name.

    "Decentralized Identifiers (DIDs)" also answers to "Decentralized
    Identifiers" and "DIDs", so tailored labels match the sources.
    """
    name = name.strip()
    aliases = {name}
    if name.endswith(")") and "(" in name:
        base, paren = name.rsplit("(", 1)
        aliases.add(base.strip())
        aliases.add(paren.rstrip(")").strip())
    return {alias.casefold() for alias in aliases if alias}


def known_skills():
    """Union of every skill named anywhere under documents/sources/."""
    known = set()

    def add(names):
        for name in names or []:
            known.update(_skill_aliases(str(name)))

    languages = load_yaml(SOURCES / "skills" / "languages.yml")
    for tier in languages.values():
        add(tier)
    add(load_yaml(SOURCES / "skills" / "frameworks.yml"))
    add(load_yaml(SOURCES / "skills" / "methodology.yml"))
    for folder in ("experience", "projects"):
        for path in sorted((SOURCES / folder).glob("*.yml")):
            add(load_yaml(path).get("skills"))
    add((load_yaml(SOURCES / "about" / "education.yml")).get("skills"))
    return known


def validate_skills(groups, extra, warn):
    known = known_skills()
    for name in extra:
        known.update(_skill_aliases(str(name)))
    for group in groups:
        for item in group["items"]:
            if not _skill_aliases(item) & known:
                warn(f"skill not found in documents/sources/: {item!r}")


def resolve_skill_groups(config, warn):
    """Expand the config's skills section.

    Each group is {group: <label>, items: [...]} and/or
    {group: <label>, from: <selector>} where <selector> is one of
    "languages", "languages.<tier>", "frameworks", "methodology".
    A top-level `extra-skills:` list allowlists tailored labels that the
    sources do not spell out verbatim (e.g. "EVM", "Microservices").
    """
    groups = []
    for entry in config.get("skills", []):
        label = entry.get("group")
        if not label:
            raise ConfigError(f"skills group missing 'group' label: {entry!r}")
        items = list(entry.get("items") or [])
        selector = entry.get("from")
        if selector:
            parts = selector.split(".")
            data = load_yaml(SOURCES / "skills" / f"{parts[0]}.yml")
            if len(parts) == 2:
                if not isinstance(data, dict) or parts[1] not in data:
                    raise ConfigError(f"unknown skills selector: {selector!r}")
                items.extend(data[parts[1]])
            elif isinstance(data, list):
                items.extend(data)
            else:
                raise ConfigError(
                    f"selector {selector!r} needs a tier (e.g. languages.expert)"
                )
        if not items:
            raise ConfigError(f"skills group {label!r} resolved to no items")
        groups.append({"group": label, "items": [str(i) for i in items]})
    validate_skills(groups, config.get("extra-skills") or [], warn)
    return groups


def resolve_bullets(entry, source, source_path):
    """Resolve a config entry's bullets against its source description."""
    pool = parse_bullets(source.get("description"))
    spec = entry.get("bullets", "all")
    if spec == "all":
        return list(pool)
    resolved = []
    for item in spec:
        if isinstance(item, str):
            resolved.append(item)
        elif isinstance(item, dict) and "use" in item:
            index = item["use"]
            if not isinstance(index, int) or not 1 <= index <= len(pool):
                raise ConfigError(
                    f"{source_path.name}: bullet index {index!r} out of range "
                    f"(source has {len(pool)} bullets)"
                )
            resolved.append(pool[index - 1])
        else:
            raise ConfigError(f"bad bullet spec {item!r} (string or {{use: N}})")
    if not resolved:
        raise ConfigError(f"{source_path.name}: entry resolved to no bullets")
    return resolved


def resolve_experience(config):
    entries = []
    for entry in config.get("experience", []):
        path = SOURCES / "experience" / f"{entry['source']}.yml"
        source = load_yaml(path)
        entries.append({
            "title": entry.get("title", source["title"]),
            "company": source["company"],
            "location": source.get("location", ""),
            "dates": format_range(source["start"], source.get("end")),
            "bullets": resolve_bullets(entry, source, path),
        })
    return entries


def resolve_projects(config):
    entries = []
    for entry in config.get("projects", []):
        path = SOURCES / "projects" / f"{entry['source']}.yml"
        source = load_yaml(path)
        dates = entry.get("dates") or format_range(
            source["start"], source.get("end"), month=False
        )
        entries.append({
            "title": entry.get("title", source["title"]),
            "dates": dates,
            "bullets": resolve_bullets(entry, source, path),
        })
    return entries


def resolve_education(config):
    source = load_yaml(SOURCES / "about" / "education.yml")
    title = config.get("education-title") or f"{source['degree']} in {source['field']}"
    return {
        "title": title,
        "school": source["school"],
        "dates": format_range(source["start"], source["end"], month=False),
    }


def _sidebar_block(heading, body_lines):
    lines = [f"{{\\bfseries {heading}}}\\\\[2pt]", "\\rule{\\linewidth}{0.4pt}\\\\[4pt]"]
    lines.extend(body_lines)
    return lines


def _main_heading(heading):
    return [f"{{\\bfseries {heading}}}\\\\[2pt]", "\\rule{\\linewidth}{0.4pt}\\\\[4pt]"]


def _itemize(bullets):
    lines = ["\\begin{itemize}[leftmargin=*, nosep, topsep=2pt]"]
    lines.extend(f"  \\item \\small{{{latex_escape(b)}}}" for b in bullets)
    lines.append("\\end{itemize}")
    return lines


def render(config, warn):
    profile = load_yaml(SOURCES / "about" / "profile.yml")
    honors = load_yaml(SOURCES / "about" / "honors.yml") or []
    organizations = load_yaml(SOURCES / "about" / "organizations.yml") or []
    skills = resolve_skill_groups(config, warn)
    experience = resolve_experience(config)
    projects = resolve_projects(config)
    education = resolve_education(config)

    name = latex_escape(profile["full-name"])
    email = latex_escape(profile["email"])

    out = [
        f"%% {config.get('description', 'Role-tailored CV')}",
        "%% GENERATED by tools/generate_cv.py - do not edit by hand.",
        f"%% Role config: documents/cv/roles/{config['_name']}.yml",
        "%% Facts: documents/sources/ (regenerate after editing either).",
        "%% Compile with: lualatex <file>.tex",
        "",
        "\\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",
        f"  {{\\Huge \\textbf{{{name}}}}}\\\\[2pt]",
        f"  {{\\large {latex_escape(config['headline'])}}}",
        "  \\par",
        "}",
        "\\vspace{14pt}",
        "",
        "\\begin{paracol}{2}",
        "\\raggedright",
        "\\small",
    ]

    # --- Sidebar: Contact ---
    contact = [f"\\href{{mailto:{profile['email']}}}{{{email}}}\\\\[2pt]"]
    contact.append(f"{latex_escape(profile['phone'])}\\\\[2pt]")
    for key, label in (
        ("website", "Website"),
        ("linkedin", "LinkedIn"),
        ("github", "GitHub"),
        ("twitter", "Twitter"),
    ):
        if profile.get(key):
            contact.append(f"\\href{{{profile[key]}}}{{{label}}}\\\\[2pt]")
    contact[-1] = contact[-1].removesuffix("\\\\[2pt]")
    out.extend(_sidebar_block("Contact", contact))
    out.append("")
    out.append("\\vspace{8pt}")
    out.append("")

    # --- Sidebar: Skills ---
    skill_lines = []
    for i, group in enumerate(skills):
        gap = "[4pt]" if i == len(skills) - 1 else "[5pt]"
        skill_lines.append(f"\\textbf{{{latex_escape(group['group'])}}}\\\\[1pt]")
        items = ", ".join(latex_escape(item) for item in group["items"])
        skill_lines.append(f"{items}\\\\{gap}")
    out.extend(_sidebar_block("Skills", skill_lines))
    out.append("")
    out.append("\\vspace{8pt}")
    out.append("")

    # --- Sidebar: Honors ---
    if honors:
        honor_lines = []
        for honor in honors:
            honor_lines.append(f"\\textbf{{{latex_escape(honor['title'])}}}\\\\[1pt]")
            year = honor["date"].year if hasattr(honor.get("date"), "year") else honor.get("date", "")
            honor_lines.append(
                f"{latex_escape(honor['institution'])} \\hfill \\textit{{{year}}}\\\\[4pt]"
            )
        out.extend(_sidebar_block("Honors", honor_lines))
        out.append("")
        out.append("\\vspace{8pt}")
        out.append("")

    # --- Sidebar: Organizations ---
    if organizations:
        org_lines = []
        for i, org in enumerate(organizations):
            gap = "[2pt]" if i == len(organizations) - 1 else "[4pt]"
            org_lines.append(f"\\textbf{{{latex_escape(org['name'])}}}\\\\[1pt]")
            org_lines.append(f"{latex_escape(org['title'])}\\\\{gap}")
        out.extend(_sidebar_block("Organizations", org_lines))
        out.append("")
        out.append("\\vspace{8pt}")
        out.append("")

    out.append("")
    out.append("\\switchcolumn")
    out.append("\\normalsize")
    out.append("\\raggedright")

    # --- Main: Experience ---
    out.extend(_main_heading("Experience"))
    for i, job in enumerate(experience):
        out.append(
            f"\\textbf{{{latex_escape(job['title'])}}} \\hfill "
            f"\\textit{{{job['dates']}}}\\\\"
        )
        location = latex_escape(job["location"])
        company = latex_escape(job["company"])
        out.append(f"\\textit{{{company} --- {location}}}" if location else f"\\textit{{{company}}}")
        out.extend(_itemize(job["bullets"]))
        out.append("\\vspace{6pt}" if i == len(experience) - 1 else "\\vspace{4pt}")
    out.append("")

    # --- Main: Projects ---
    if projects:
        out.extend(_main_heading("Projects"))
        for i, project in enumerate(projects):
            out.append(
                f"\\textbf{{{latex_escape(project['title'])}}} \\hfill "
                f"\\textit{{{latex_escape(project['dates'])}}}"
            )
            out.extend(_itemize(project["bullets"]))
            out.append("\\vspace{6pt}" if i == len(projects) - 1 else "\\vspace{4pt}")
        out.append("")

    # --- Main: Publications (optional, literal entries in the role config) ---
    publications = config.get("publications", [])
    if publications:
        out.extend(_main_heading("Publications \\& Talks"))
        out.append("\\begin{itemize}[leftmargin=*, nosep, topsep=2pt]")
        for pub in publications:
            text = latex_escape(pub["text"])
            if pub.get("url"):
                text += f" \\href{{{pub['url']}}}{{[link]}}"
            out.append(f"  \\item \\small{{{text}}}")
        out.append("\\end{itemize}")
        out.append("\\vspace{6pt}")
        out.append("")

    # --- Main: Education ---
    out.extend(_main_heading("Education"))
    out.append(
        f"\\textbf{{{latex_escape(education['title'])}}} \\hfill "
        f"\\textit{{{education['dates']}}}\\\\"
    )
    out.append(f"\\textit{{{latex_escape(education['school'])}}}")
    out.append("\\vspace{4pt}")
    out.extend(["", "", "\\end{paracol}", "", "\\end{document}", ""])
    return "\n".join(out)


def list_roles():
    return sorted(path.stem for path in ROLES_DIR.glob("*.yml"))


def generate(role, output=None, warn=None):
    warn = warn or (lambda msg: print(f"warning: {role}: {msg}", file=sys.stderr))
    path = ROLES_DIR / f"{role}.yml"
    config = load_yaml(path)
    if not isinstance(config, dict) or "headline" not in config:
        raise ConfigError(f"{path}: role config needs at least a 'headline'")
    config["_name"] = role
    target = Path(output) if output else OUT_DIR / config.get("output", f"main_example_{role.replace('-', '_')}.tex")
    target.write_text(render(config, warn), encoding="utf-8")
    return target


def build_parser():
    parser = argparse.ArgumentParser(
        description="Generate role-tailored LaTeX CVs from documents/sources/."
    )
    parser.add_argument("roles", nargs="*", help="role config names (documents/cv/roles/<name>.yml)")
    parser.add_argument("--all", action="store_true", help="generate every role config")
    parser.add_argument("--list", action="store_true", help="list available role configs")
    parser.add_argument("--output", help="explicit output path (single role only)")
    return parser


def main(argv=None):
    args = build_parser().parse_args(argv)
    if args.list:
        for role in list_roles():
            print(role)
        return 0
    roles = list_roles() if args.all else args.roles
    if not roles:
        build_parser().error("give one or more roles, --all, or --list")
    if args.output and len(roles) != 1:
        build_parser().error("--output only makes sense with exactly one role")
    try:
        for role in roles:
            target = generate(role, output=args.output)
            print(f"wrote {target.relative_to(REPO)}")
    except ConfigError as exc:
        print(f"error: {exc}", file=sys.stderr)
        return 1
    return 0


if __name__ == "__main__":
    sys.exit(main())