#!/bin/bash
# =============================================================================
# gen_channel_map.sh - Build docs/LTC2980_channel_map.csv from settings/*.conf
# Version : V1.0.0
# Date    : 2026-08-27
# Author  : ETWen
# =============================================================================
# Runs on the DEV machine, not the DUT. Reads every LTC2980 margin settings
# file and flattens CH<n>_VNOM / CH<n>_NET into one CSV:
#
#     Board,CONN,Ch,NetName,Vnom
#     CB,CONN13,CH0,V5P0_ALW,5.0
#
# NC channels keep their literal NC / "-" so the page numbering still lines up
# (ch/8 -> CHIPS[] index, ch%8 -> LTC2977 PAGE). Do not filter them out.
#
# Usage:
#   tools/gen_channel_map.sh                 # write docs/LTC2980_channel_map.csv
#   tools/gen_channel_map.sh -              # write to stdout
# =============================================================================
set -eu

REPO_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
SET_DIR="${REPO_ROOT}/src/Script_ABC_Blanton/Blanton_Script/LTC2980_Margin_Script/settings"
OUT="${1:-${REPO_ROOT}/docs/LTC2980_channel_map.csv}"

[ -d "${SET_DIR}" ] || { echo "settings dir not found: ${SET_DIR}" >&2; exit 1; }

# 3-argument match(str, regex, array) is a gawk extension. Under mawk it is a
# syntax error at best and an empty CSV at worst - fail loudly instead.
awk 'BEGIN { if (match("a", /a/, m) != 1) exit 1 }' 2>/dev/null \
    || { echo "need gawk (3-arg match); this awk is: $(awk --version 2>&1 | head -1)" >&2; exit 1; }

gen() {
    printf 'Board,CONN,Ch,NetName,Vnom\n'
    # CB first, then SWB0/SWB1 CONN13..CONN16 - matches the physical walk order.
    for f in "${SET_DIR}"/Blanton_CB_CONN*.conf \
             "${SET_DIR}"/Blanton_SWB0_CONN*.conf \
             "${SET_DIR}"/Blanton_SWB1_CONN*.conf ; do
        [ -f "${f}" ] || continue
        base="$(basename "${f}" .conf)"          # Blanton_SWB0_CONN13
        board="$(echo "${base}" | cut -d_ -f2)"  # SWB0
        conn="$(echo  "${base}" | cut -d_ -f3)"  # CONN13

        # .conf files are LF per .gitattributes, but strip CR anyway - a stray
        # CR would land inside the net name and travel into the CSV unseen.
        sed 's/\r$//' "${f}" | awk -v b="${board}" -v c="${conn}" '
            match($0, /^CH([0-9]+)_VNOM="([^"]*)"[^"]*CH[0-9]+_NET="([^"]*)"/, m) {
                printf "%s,%s,CH%s,%s,%s\n", b, c, m[1], m[3], m[2]
            }'
    done
}

if [ "${OUT}" = "-" ]; then
    gen
else
    gen > "${OUT}"
    echo "wrote ${OUT}  ($(($(wc -l < "${OUT}") - 1)) channels)"
fi