#!/usr/bin/env bash
# =============================================================================
# render_diagrams.sh — one-click render of all CS3319 architecture/flow diagrams.
#
# Renders every source under docs/diagrams/src/ into SVG (+ PDF where the tool
# supports it) into docs/diagrams/svg/ and docs/diagrams/pdf/.
#
#   .mmd  -> Mermaid      (mmdc, falls back to npx @mermaid-js/mermaid-cli)
#   .d2   -> D2           (d2, auto-installs via scoop on Windows if missing)
#   .dot  -> Graphviz DOT (dot)
#   .puml -> PlantUML/C4  (java -jar scripts/.cache/plantuml.jar, auto-downloaded)
#
# The script degrades gracefully: a missing tool is reported and skipped,
# it never aborts the whole run. Run it again after installing the missing tool.
#
# Usage:
#   bash scripts/render_diagrams.sh          # render everything
#   bash scripts/render_diagrams.sh --svg    # SVG only (skip PDFs)
# =============================================================================
set -uo pipefail

# ---- resolve paths relative to this script (works from any CWD) ----
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
SRC="$ROOT/docs/diagrams/src"
SVG_DIR="$ROOT/docs/diagrams/svg"
PDF_DIR="$ROOT/docs/diagrams/pdf"
CACHE="$SCRIPT_DIR/.cache"
PLANTUML_JAR="$CACHE/plantuml.jar"
PLANTUML_URL="https://github.com/plantuml/plantuml/releases/latest/download/plantuml.jar"

DO_PDF=1
[ "${1:-}" = "--svg" ] && DO_PDF=0

mkdir -p "$SVG_DIR" "$PDF_DIR" "$CACHE"

# ---- color helpers (works in plain terminals too) ----
if [ -t 1 ]; then
  G=$'\033[32m'; Y=$'\033[33m'; R=$'\033[31m'; B=$'\033[1m'; N=$'\033[0m'
else
  G=""; Y=""; R=""; B=""; N=""
fi
ok()   { printf "%s✓%s %s\n" "$G" "$N" "$*"; }
skip() { printf "%s·%s %s\n" "$Y" "$N" "$*"; }
fail() { printf "%s✗%s %s\n" "$R" "$N" "$*"; }
hdr()  { printf "\n%s== %s ==%s\n" "$B" "$*" "$N"; }

declare -a RESULTS=()
record() { RESULTS+=("$1"); }   # $1 = "✓|✗ file"

# ---- tool availability (with best-effort auto-setup) ----
hdr "Checking renderers"

# Mermaid (mmdc)
MMDC=""
if command -v mmdc >/dev/null 2>&1; then MMDC="mmdc";
elif command -v npx >/dev/null 2>&1; then MMDC="npx --yes @mermaid-js/mermaid-cli"; fi
[ -n "$MMDC" ] && ok "Mermaid: $MMDC" || skip "Mermaid: NOT found (install: npm i -g @mermaid-js/mermaid-cli)"

# D2
if ! command -v d2 >/dev/null 2>&1; then
  skip "d2 not found — attempting auto-install (scoop)..."
  if command -v scoop >/dev/null 2>&1; then
    scoop install d2 >/dev/null 2>&1 && ok "d2 installed via scoop" || skip "scoop install d2 failed"
  fi
fi
command -v d2 >/dev/null 2>&1 && ok "D2: $(command -v d2)" || skip "D2: NOT found (Windows: scoop install d2 | macOS: brew install d2)"

# Graphviz
command -v dot >/dev/null 2>&1 && ok "Graphviz: $(dot -V 2>&1)" || skip "Graphviz: NOT found (install graphviz)"

# PlantUML (java + jar)
PUML=""
if command -v java >/dev/null 2>&1; then
  if [ ! -f "$PLANTUML_JAR" ]; then
    skip "plantuml.jar missing — downloading to $PLANTUML_JAR ..."
    if curl -L --fail -o "$PLANTUML_JAR" "$PLANTUML_URL" 2>/dev/null; then ok "plantuml.jar downloaded";
    else rm -f "$PLANTUML_JAR"; skip "download failed (offline?)"; fi
  fi
  [ -f "$PLANTUML_JAR" ] && PUML="java -jar \"$PLANTUML_JAR\"" && ok "PlantUML: $(java -jar "$PLANTUML_JAR" -version 2>/dev/null | head -1)"
else
  skip "PlantUML: java NOT found (install a JDK)"
fi

# ---- helpers ----
have() { command -v "$1" >/dev/null 2>&1; }

# =====================================================================
#  Mermaid  (.mmd)
# =====================================================================
hdr "Mermaid  (.mmd)"
if [ -n "$MMDC" ]; then
  shopt -s nullglob
  for f in "$SRC"/*.mmd; do
    b="$(basename "$f" .mmd)"
    if $MMDC -i "$f" -o "$SVG_DIR/$b.svg" >/dev/null 2>&1; then ok "$b.svg"; record "ok $b.mmd";
    else fail "$b (mmdc error)"; record "bad $b.mmd"; fi
    if [ "$DO_PDF" = 1 ] && $MMDC -i "$f" -o "$PDF_DIR/$b.pdf" >/dev/null 2>&1; then :; fi
  done
  shopt -u nullglob
else
  skip "no .mmd rendered (mmdc missing)"
fi

# =====================================================================
#  D2  (.d2)
# =====================================================================
hdr "D2  (.d2)"
if have d2; then
  shopt -s nullglob
  for f in "$SRC"/*.d2; do
    b="$(basename "$f" .d2)"
    if d2 "$f" "$SVG_DIR/$b.svg" >/dev/null 2>&1; then ok "$b.svg"; record "ok $b.d2";
    else fail "$b (d2 error)"; record "bad $b.d2"; fi
    [ "$DO_PDF" = 1 ] && d2 "$f" "$PDF_DIR/$b.pdf" >/dev/null 2>&1 || true
  done
  shopt -u nullglob
else
  skip "no .d2 rendered (d2 missing)"
fi

# =====================================================================
#  Graphviz  (.dot)
# =====================================================================
hdr "Graphviz  (.dot)"
if have dot; then
  shopt -s nullglob
  for f in "$SRC"/*.dot; do
    b="$(basename "$f" .dot)"
    if dot -Tsvg "$f" -o "$SVG_DIR/$b.svg" >/dev/null 2>&1; then ok "$b.svg"; record "ok $b.dot";
    else fail "$b (dot error)"; record "bad $b.dot"; fi
    [ "$DO_PDF" = 1 ] && dot -Tpdf "$f" -o "$PDF_DIR/$b.pdf" >/dev/null 2>&1 || true
  done
  shopt -u nullglob
else
  skip "no .dot rendered (graphviz missing)"
fi

# =====================================================================
#  PlantUML / C4  (.puml)
# =====================================================================
hdr "PlantUML / C4  (.puml)"
if [ -n "$PUML" ]; then
  shopt -s nullglob
  for f in "$SRC"/*.puml; do
    b="$(basename "$f" .puml)"
    # plantuml writes <name>.svg next to the source by default; render then move.
    if ( cd "$SRC" && eval "$PUML" -tsvg -charset UTF-8 "$(basename "$f")" >/dev/null 2>&1 ); then
      if [ -f "$SRC/$b.svg" ]; then mv -f "$SRC/$b.svg" "$SVG_DIR/$b.svg"; ok "$b.svg"; record "ok $b.puml";
      else fail "$b (no svg produced)"; record "bad $b.puml"; fi
    else
      fail "$b (plantuml error)"; record "bad $b.puml"
    fi
    if [ "$DO_PDF" = 1 ]; then
      ( cd "$SRC" && eval "$PUML" -tpdf -charset UTF-8 "$(basename "$f")" >/dev/null 2>&1 ) && \
        [ -f "$SRC/$b.pdf" ] && mv -f "$SRC/$b.pdf" "$PDF_DIR/$b.pdf" || true
    fi
  done
  shopt -u nullglob
else
  skip "no .puml rendered (java/plantuml.jar missing)"
fi

# =====================================================================
#  Summary
# =====================================================================
hdr "Summary"
SVG_COUNT=$(find "$SVG_DIR" -maxdepth 1 -name '*.svg' 2>/dev/null | wc -l | tr -d ' ')
PDF_COUNT=$(find "$PDF_DIR" -maxdepth 1 -name '*.pdf' 2>/dev/null | wc -l | tr -d ' ')
BAD=$(printf '%s\n' "${RESULTS[@]}" 2>/dev/null | grep -c '^bad' || true)
printf "SVG: %s   PDF: %s   failed sources: %s\n" "$SVG_COUNT" "$PDF_COUNT" "$BAD"
[ "$BAD" = "0" ] && ok "all available sources rendered" || fail "$BAD source(s) failed — see messages above"
printf "SVG dir: %s\nPDF dir: %s\n" "$SVG_DIR" "$PDF_DIR"
exit 0