#!/usr/bin/env bash
# Opt-in wiring between gstack's Claude hook manager and Memorable.
set -u

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
ROOT_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
SETTINGS_HOOK="$SCRIPT_DIR/gstack-settings-hook"
SETTINGS_FILE="${GSTACK_SETTINGS_FILE:-${CLAUDE_CONFIG_DIR:-$HOME/.claude}/settings.json}"
MEMORABLE_HOOK="$ROOT_DIR/hosts/claude/hooks/memorable-user-prompt-hook"
HOOK_SOURCE="gstack-memorable"

usage() {
  cat <<EOF
Usage: gstack-memorable <enable|disable|status>

  enable   Enable Memorable, then register its Claude UserPromptSubmit hook
  disable  Remove the gstack hook, then disable Memorable
  status   Report Memorable CLI availability and hook registration
EOF
}

resolve_memorable() {
  if [ -n "${MEMORABLE_BIN:-}" ]; then
    [ -f "$MEMORABLE_BIN" ] && [ -x "$MEMORABLE_BIN" ] || return 1
    printf '%s\n' "$MEMORABLE_BIN"
    return 0
  fi

  if [ -n "${HOME:-}" ] && [ -f "$HOME/.memorable/bin/memorable" ] && [ -x "$HOME/.memorable/bin/memorable" ]; then
    printf '%s\n' "$HOME/.memorable/bin/memorable"
    return 0
  fi

  command -v memorable 2>/dev/null
}

require_memorable() {
  MEMORABLE_CLI="$(resolve_memorable 2>/dev/null)" || {
    echo "gstack-memorable: Memorable CLI not found; install memorable-cli or set MEMORABLE_BIN." >&2
    return 1
  }
  [ -n "$MEMORABLE_CLI" ] || return 1
}

# Memorable's own installer registers the SAME UserPromptSubmit hook, under
# its own name and outside gstack's table. `memorable start`, `memorable setup`
# and `memorable install-hooks` all do it, and that is the documented way to
# install the CLI — so on most machines it is already there before gstack is
# asked. Registering ours beside it runs the same command twice on every
# prompt: context injected twice, and the session captured twice against the
# user's own extraction allowance.
#
# Matched on the command, not on a tag, for the same reason the hook table in
# gstack-settings-hook matches on command: Claude Code rewrites settings and
# private tags do not survive it.
memorable_own_hook() {
  [ -f "$SETTINGS_FILE" ] || return 1
  GSTACK_SETTINGS_PATH="$SETTINGS_FILE" bun -e '
    const fs = require("fs");
    let s = {};
    try { s = JSON.parse(fs.readFileSync(process.env.GSTACK_SETTINGS_PATH, "utf8")); } catch { process.exit(1); }
    const groups = (s.hooks && s.hooks.UserPromptSubmit) || [];
    const ours = process.env.GSTACK_MEMORABLE_HOOK || "";
    for (const g of groups) {
      for (const h of (g.hooks || [])) {
        const c = String(h.command || "");
        if (c === ours || c.includes("memorable-user-prompt-hook")) continue;
        if (/memorable/i.test(c) && /hook\s+user-prompt/.test(c)) { console.log(c); process.exit(0); }
      }
    }
    process.exit(1);
  ' 2>/dev/null
}

hook_present() {
  [ -x "$SETTINGS_HOOK" ] || return 1
  if "$SETTINGS_HOOK" list-sources 2>/dev/null |
    awk -F '\t' -v source="$HOOK_SOURCE" '
      $1 == "UserPromptSubmit" && $2 == source { found = 1 }
      END { exit(found ? 0 : 1) }
    '; then
    return 0
  fi

  # Claude Code may strip the private source tag when it rewrites settings.
  # A no-op diff still proves that the canonical command itself is present.
  "$SETTINGS_HOOK" diff-event \
    --event UserPromptSubmit \
    --command "$MEMORABLE_HOOK" \
    --source "$HOOK_SOURCE" 2>/dev/null |
    awk '
      /^--- BEFORE$/ { section = 1; saw_before = 1; next }
      /^--- AFTER$/  { section = 2; saw_after = 1; next }
      section == 1 { before = before $0 "\n" }
      section == 2 { after = after $0 "\n" }
      END { exit(saw_before && saw_after && before == after ? 0 : 1) }
    '
}

enable_memorable() {
  local existing
  require_memorable || return 1
  [ -x "$SETTINGS_HOOK" ] || {
    echo "gstack-memorable: missing hook manager: $SETTINGS_HOOK" >&2
    return 1
  }
  [ -x "$MEMORABLE_HOOK" ] || {
    echo "gstack-memorable: missing executable hook: $MEMORABLE_HOOK" >&2
    return 1
  }

  existing="$(GSTACK_MEMORABLE_HOOK="$MEMORABLE_HOOK" memorable_own_hook)" && {
    cat >&2 <<EOF
gstack-memorable: Memorable already registers this hook itself:
  $existing

Registering gstack's as well would run it twice on every prompt: injected
twice, and the session captured twice against your extraction allowance.

Keep the one you have, or hand it to gstack: delete that entry from
  $SETTINGS_FILE
and run this again. Memorable has no command to remove its own hook.
EOF
    return 1
  }

  "$MEMORABLE_CLI" enable || return $?
  "$SETTINGS_HOOK" ensure-event \
    --event UserPromptSubmit \
    --command "$MEMORABLE_HOOK" \
    --source "$HOOK_SOURCE"
}

disable_memorable() {
  local hook_rc=0 cli_rc=0

  if [ -x "$SETTINGS_HOOK" ]; then
    "$SETTINGS_HOOK" remove-source --source "$HOOK_SOURCE" || hook_rc=$?
  else
    echo "gstack-memorable: missing hook manager: $SETTINGS_HOOK" >&2
    hook_rc=1
  fi

  if require_memorable; then
    "$MEMORABLE_CLI" disable || cli_rc=$?
  else
    cli_rc=1
  fi

  [ "$hook_rc" -eq 0 ] && [ "$cli_rc" -eq 0 ]
}

status_memorable() {
  local existing
  if MEMORABLE_CLI="$(resolve_memorable 2>/dev/null)" && [ -n "$MEMORABLE_CLI" ]; then
    printf 'Memorable CLI: available (%s)\n' "$MEMORABLE_CLI"
  else
    echo "Memorable CLI: unavailable"
  fi

  if hook_present; then
    echo "Claude UserPromptSubmit hook: registered by gstack"
  elif existing="$(GSTACK_MEMORABLE_HOOK="$MEMORABLE_HOOK" memorable_own_hook)"; then
    printf 'Claude UserPromptSubmit hook: registered by Memorable itself (%s)\n' "$existing"
    echo "  gstack is not managing it; 'gstack-memorable enable' would double it."
  else
    echo "Claude UserPromptSubmit hook: not registered"
  fi
}

case "${1:-}" in
  enable)  enable_memorable ;;
  disable) disable_memorable ;;
  status)  status_memorable ;;
  -h|--help|help) usage ;;
  *) usage >&2; exit 1 ;;
esac