#!/usr/bin/env bash
# export_for_msla.sh — KiCad Gerber export + pm4n generation for Anycubic Photon Mono 4
#
# Usage:
#   ./export_for_msla.sh [OPTIONS] <path/to/board.kicad_pcb>
#
# Options:
#   --layers  LAYER,LAYER,...  KiCad layer names to export (default: F.Cu)
#   --invert  LAYER,LAYER,...  Layers to invert  (comma-separated, e.g. F.Cu,B.Mask)
#   --mirror  LAYER,LAYER,...  Layers to mirror  (comma-separated, e.g. F.Cu,F.Mask)
#   --exposure SECONDS         Exposure time in seconds (default: 60)
#   --dummy   FILE             Dummy .pm4n template (default: Dummy.pm4n beside this script)
#   --out     DIR              Output directory (default: ./output)
#   --dpmm    N                Render resolution in dots/mm (default: native 58.824)
#   --pos     X,Y              Board position on LCD in mm (default: centred)
#   -h, --help                 Show this help
#
# Example:
#   ./export_for_msla.sh --invert F.Cu,B.Mask --mirror F.Cu,F.Mask panel/Flow_Controller_Panel.kicad_pcb
#
# Layer name → Gerber filename mapping (KiCad default):
#   F.Cu    → <board>-F_Cu.gbr
#   B.Cu    → <board>-B_Cu.gbr
#   F.Mask  → <board>-F_Mask.gbr
#   B.Mask  → <board>-B_Mask.gbr
#   F.SilkS → <board>-F_Silkscreen.gbr
#   (etc.)

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PYTHON="${PYTHON:-python3}"
CONVERTER="$SCRIPT_DIR/gerber_to_pm4n.py"

# ---- defaults ----
LAYERS="F.Cu"
INVERT_LAYERS=""
MIRROR_LAYERS=""
EXPOSURE="60"
DUMMY="$SCRIPT_DIR/Dummy.pm4n"
OUT_DIR="./output"
DPMM=""
POS=""

# ---- helpers ----
usage() {
    sed -n '/^# Usage/,/^[^#]/{ /^#/{ s/^# \{0,1\}//; p } }' "$0"
    exit 0
}

contains() {   # contains <list> <item>  — comma-separated list membership
    local list="$1" item="$2"
    echo "$list" | tr ',' '\n' | grep -qx "$item"
}

layer_to_filename() {   # KiCad layer name → Gerber filename stem
    local layer="$1"
    echo "$layer" | sed 's/\./_/g'
}

# ---- parse arguments ----
PCB_FILE=""
while [[ $# -gt 0 ]]; do
    case "$1" in
        --layers)   LAYERS="$2";         shift 2 ;;
        --invert)   INVERT_LAYERS="$2";  shift 2 ;;
        --mirror)   MIRROR_LAYERS="$2";  shift 2 ;;
        --exposure) EXPOSURE="$2";       shift 2 ;;
        --dummy)    DUMMY="$2";          shift 2 ;;
        --out)      OUT_DIR="$2";        shift 2 ;;
        --dpmm)     DPMM="$2";           shift 2 ;;
        --pos)      POS="$2";            shift 2 ;;
        -h|--help)  usage ;;
        -*)         echo "Unknown option: $1"; exit 1 ;;
        *)          PCB_FILE="$1";       shift ;;
    esac
done

if [[ -z "$PCB_FILE" ]]; then
    echo "ERROR: no .kicad_pcb file specified"
    echo "Usage: $0 [OPTIONS] <board.kicad_pcb>"
    exit 1
fi

if [[ ! -f "$PCB_FILE" ]]; then
    echo "ERROR: file not found: $PCB_FILE"
    exit 1
fi

if [[ ! -f "$DUMMY" ]]; then
    echo "ERROR: dummy .pm4n not found: $DUMMY"
    echo "Place Dummy.pm4n next to export.sh, or pass --dummy <path>"
    exit 1
fi

# ---- derive names ----
BOARD_NAME="$(basename "$PCB_FILE" .kicad_pcb)"
GERBERS_DIR="$OUT_DIR/gerbers"
PM4N_DIR="$OUT_DIR/pm4n"

mkdir -p "$GERBERS_DIR" "$PM4N_DIR"

# ---- Step 1: export Gerbers via kicad-cli ----
echo "=== Exporting Gerbers from KiCad ==="
echo "  Board:  $PCB_FILE"
echo "  Layers: $LAYERS"
echo "  Output: $GERBERS_DIR"
echo ""

kicad-cli pcb export gerbers \
    --output "$GERBERS_DIR" \
    --layers "$LAYERS" \
    --no-protel-ext \
    --subtract-soldermask \
    "$PCB_FILE"

echo ""

# ---- Step 2: convert each layer to .pm4n ----
echo "=== Converting Gerbers to .pm4n ==="

IFS=',' read -ra LAYER_LIST <<< "$LAYERS"
for LAYER in "${LAYER_LIST[@]}"; do
    LAYER_STEM="$(layer_to_filename "$LAYER")"
    GBR_FILE="$GERBERS_DIR/${BOARD_NAME}-${LAYER_STEM}.gbr"

    if [[ ! -f "$GBR_FILE" ]]; then
        echo "  WARNING: expected Gerber not found: $GBR_FILE — skipping"
        continue
    fi

    OUT_PM4N="$PM4N_DIR/${BOARD_NAME}-${LAYER_STEM}.pm4n"

    # Build flags
    FLAGS=()
    if contains "$INVERT_LAYERS" "$LAYER"; then FLAGS+=(--invert); fi
    if contains "$MIRROR_LAYERS" "$LAYER"; then FLAGS+=(--mirror); fi
    [[ -n "$DPMM" ]] && FLAGS+=(--dpmm "$DPMM")
    [[ -n "$POS"  ]] && FLAGS+=(--pos "$POS")

    echo "  Layer: $LAYER"
    echo "    Gerber:  $GBR_FILE"
    echo "    pm4n:    $OUT_PM4N"
    echo "    Flags:   ${FLAGS[*]:-<none>}  exposure=${EXPOSURE}s"

    "$PYTHON" "$CONVERTER" \
        "$DUMMY" \
        "$GBR_FILE" \
        --output "$OUT_PM4N" \
        --exposure "$EXPOSURE" \
        "${FLAGS[@]}"
    echo ""
done

echo "=== Done ==="
echo "pm4n files in: $PM4N_DIR"