#!/usr/bin/env bash
set -euo pipefail

# Resume builder wrapper that runs Pandoc inside a Docker container.
#
# Layout assumptions (relative to repo root):
# - Input Markdown files:  resumes/input/*.md
# - Output artifacts:      output/*.pdf and output/*.docx
# - Templates:             templates/resume-template.tex, templates/resume-reference.docx
#
# Usage:
#   bin/resume-build                      # build all inputs to both PDF and DOCX (single container)
#
# Config via env vars:
#   PANDOC_IMAGE   (default: pandoc/latex:latest)
#   PDF_ENGINE     (default: xelatex)
#   TEMPLATE       (default: templates/resume-template.tex)
#   REFDOC         (default: templates/resume-reference.docx)
#   INPUT_DIR      (default: resumes/input)
#   OUTPUT_DIR     (default: output)

PANDOC_IMAGE=${PANDOC_IMAGE:-danteev/texlive:latest}
PDF_ENGINE=${PDF_ENGINE:-xelatex}
INPUT_DIR=${INPUT_DIR:-resumes/input}
OUTPUT_DIR=${OUTPUT_DIR:-output}
TEMPLATE=${TEMPLATE:-templates/resume-template.tex}
REFDOC=${REFDOC:-templates/resume-reference.docx}
TEXLIVE_INSTALL=${TEXLIVE_INSTALL:-""}

REPO_ROOT=$(cd "$(dirname "$0")/.." && pwd)
cd "$REPO_ROOT"

err() { echo "[resume-build] $*" >&2; }
log() { echo "[resume-build] $*"; }

require() {
  command -v "$1" >/dev/null 2>&1 || { err "Missing dependency: $1"; exit 1; }
}

run_docker() {
  # Runs a command in the pandoc container with repo mounted at /data
  local user opt_user
  if user=$(id -u 2>/dev/null) && group=$(id -g 2>/dev/null); then
    opt_user=( -u "${user}:${group}" )
  else
    opt_user=()
  fi

  local cmd=( docker run --rm
    "${opt_user[@]}"
    -v "$REPO_ROOT:/data"
    -w /data
    --entrypoint /bin/sh \
    "$PANDOC_IMAGE" )

  "${cmd[@]}" -c "$*"
}

cmd_pandoc_pdf() { # echo PDF pandoc command
  local in_md=$1 out_pdf=$2 template=$3 engine=$4
  printf 'pandoc %q -o %q --from markdown+autolink_bare_uris --template=%q --pdf-engine=%q' \
    "$in_md" "$out_pdf" "$template" "$engine"
}

cmd_pandoc_docx() { # echo DOCX pandoc command
  local in_md=$1 out_docx=$2 refdoc=$3
  printf 'pandoc %q -o %q --from markdown+autolink_bare_uris --reference-doc=%q' \
    "$in_md" "$out_docx" "$refdoc"
}

build_all() {
  require docker
  [[ -d "$INPUT_DIR" ]] || { err "Input dir not found: $INPUT_DIR"; exit 1; }
  mkdir -p "$OUTPUT_DIR"
  shopt -s nullglob
  local files=( "$INPUT_DIR"/*.md )
  if (( ${#files[@]} == 0 )); then
    err "No markdown files in $INPUT_DIR"; exit 1
  fi
  local batch="set -e; if [ -n \"${TEXLIVE_INSTALL}\" ]; then tlmgr install ${TEXLIVE_INSTALL} || true; fi"; local first=1
  for f in "${files[@]}"; do
    local base md_in pdf_out docx_out
    base=$(basename "${f%.md}")
    md_in="/data/${f}"
    pdf_out="/data/${OUTPUT_DIR}/${base}.pdf"
    docx_out="/data/${OUTPUT_DIR}/${base}.docx"
    log "PDF  <- $f"
    batch+=" && "
    batch+=$(cmd_pandoc_pdf "$md_in" "$pdf_out" "/data/${TEMPLATE}" "$PDF_ENGINE")
    log "DOCX <- $f"
    batch+=" && "
    batch+=$(cmd_pandoc_docx "$md_in" "$docx_out" "/data/${REFDOC}")
  done
  run_docker "$batch"
}

usage() {
  cat <<EOF
Usage: $0
  Builds all Markdown files in "$INPUT_DIR" to both PDF and DOCX into "$OUTPUT_DIR".

Env:
  PANDOC_IMAGE=${PANDOC_IMAGE}
  INPUT_DIR=${INPUT_DIR}
  OUTPUT_DIR=${OUTPUT_DIR}
  TEMPLATE=${TEMPLATE}
  REFDOC=${REFDOC}
  PDF_ENGINE=${PDF_ENGINE}
EOF
}

main() {
  if [[ $# -gt 0 ]]; then usage; exit 1; fi
  build_all
}

main "$@"