#!/usr/bin/env bash
# mempalace-incremental-mine.sh
# Re-mines only files changed since the last run, keeping the palace current
# without full re-ingestion.
#
# Usage:
#   ./scripts/mempalace-incremental-mine.sh [workspace_dir] [palace_dir]
#
# Defaults:
#   workspace_dir  — $WIZARD_HOME or /root/wizards/bezalel
#   palace_dir     — $MEMPALACE_DIR or <workspace_dir>/.mempalace
#
# Dependencies: mempalace (vendored), find
#
# Refs: #1072 (Bezalel MemPalace Field Report)

set -euo pipefail

WORKSPACE="${1:-${WIZARD_HOME:-/root/wizards/bezalel}}"
PALACE_DIR="${2:-${MEMPALACE_DIR:-$WORKSPACE/.mempalace}}"
STAMP_FILE="$PALACE_DIR/.last_mine_ts"
PALACE_PATH="$PALACE_DIR/palace"

if [[ ! -d "$WORKSPACE" ]]; then
  echo "[mempalace-incremental-mine] ERROR: workspace not found: $WORKSPACE" >&2
  exit 1
fi

# Resolve mempalace binary — check vendored location first
MEMPALACE_BIN=""
for candidate in \
    "$WORKSPACE/.vendor/mempalace/mempalace" \
    "$WORKSPACE/.vendor/mempalace/bin/mempalace" \
    "$(command -v mempalace 2>/dev/null || true)"; do
  if [[ -x "$candidate" ]]; then
    MEMPALACE_BIN="$candidate"
    break
  fi
done

if [[ -z "$MEMPALACE_BIN" ]]; then
  echo "[mempalace-incremental-mine] ERROR: mempalace binary not found." >&2
  echo "  Vendor it at $WORKSPACE/.vendor/mempalace/ or install it globally." >&2
  exit 1
fi

mkdir -p "$PALACE_DIR"

# Determine changed files since last run
if [[ -f "$STAMP_FILE" ]]; then
  SINCE=$(cat "$STAMP_FILE")
  echo "[mempalace-incremental-mine] Mining files changed since $SINCE"
  # Find files newer than the stamp file itself
  CHANGED_FILES=$(find "$WORKSPACE" \
    -newer "$STAMP_FILE" \
    -type f \
    ! -path "*/.mempalace/*" \
    ! -path "*/.git/*" \
    ! -path "*/node_modules/*" \
    ! -path "*/__pycache__/*" \
    ! -name "*.pyc" \
    2>/dev/null || true)
else
  echo "[mempalace-incremental-mine] No prior stamp found — running full mine."
  CHANGED_FILES=""
fi

if [[ -z "$CHANGED_FILES" && -f "$STAMP_FILE" ]]; then
  echo "[mempalace-incremental-mine] No changed files detected. Palace is current."
  exit 0
fi

YAML_CONFIG="$WORKSPACE/mempalace.yaml"
if [[ ! -f "$YAML_CONFIG" ]]; then
  echo "[mempalace-incremental-mine] WARNING: $YAML_CONFIG not found." >&2
  echo "  Room taxonomy will not be applied. Create mempalace.yaml to enable routing." >&2
  YAML_ARGS=()
else
  YAML_ARGS=(--config "$YAML_CONFIG")
fi

if [[ -n "$CHANGED_FILES" ]]; then
  # Mine only the changed files
  FILE_COUNT=$(echo "$CHANGED_FILES" | wc -l | tr -d ' ')
  echo "[mempalace-incremental-mine] Mining $FILE_COUNT changed file(s)..."
  echo "$CHANGED_FILES" | xargs -I{} "$MEMPALACE_BIN" mine "${YAML_ARGS[@]}" \
    --palace "$PALACE_PATH" {} 2>&1
else
  # Full mine (first run)
  echo "[mempalace-incremental-mine] Running full mine of $WORKSPACE ..."
  "$MEMPALACE_BIN" mine "${YAML_ARGS[@]}" --palace "$PALACE_PATH" "$WORKSPACE" 2>&1
fi

# Update stamp
date -u +"%Y-%m-%dT%H:%M:%SZ" > "$STAMP_FILE"
echo "[mempalace-incremental-mine] Done. Stamp updated: $(cat "$STAMP_FILE")"