#!/bin/bash

# ============================================================================
# 10-recon.sh - Read every fact needed to choose a rooting path. READ-ONLY.
#
# This script never writes to the device. It issues no reboot, no fastboot
# command, no `settings put`, and touches no partition. tests/run_tests.sh
# enforces that with a static scan of this file, because the phone it will
# most often be pointed at is a daily driver.
#
# Output: a facts file under the cache dir, plus a decision summary naming
# which of the four paths applies and what is still unknown.
# ============================================================================

set -euo pipefail

SCRIPT_DIR="$(dirname "$(readlink -f "$0")")"
readonly SCRIPT_DIR
readonly SCRIPT_NAME="${0##*/}"

# shellcheck source=../lib/mtk_common.sh
source "$SCRIPT_DIR/../lib/mtk_common.sh"

# Properties captured verbatim into the facts file. Grouped by what they tell
# us; all are read-only.
readonly -a FACT_PROPS=(
  ro.product.manufacturer
  ro.product.model
  ro.product.name
  ro.product.device
  ro.product.first_api_level
  ro.board.platform
  ro.hardware
  ro.build.fingerprint
  ro.build.id
  ro.build.version.release
  ro.build.version.sdk
  ro.build.version.security_patch
  ro.build.type
  ro.boot.slot_suffix
  ro.boot.flash.locked
  ro.boot.verifiedbootstate
  ro.boot.vbmeta.device_state
  ro.boot.veritymode
  ro.boot.hardware
  ro.boot.bootloader
  ro.bootloader
  ro.oem_unlock_supported
  sys.oem_unlock_allowed
  ro.carrier
  gsm.sim.operator.alpha
  ro.crypto.state
)

REQUESTED_SERIAL=""
EXPLAIN_ONLY=0

usage() {
  cat <<EOF
Usage: $SCRIPT_NAME [--serial <serial>] [--explain-classification] [--help]

Reads device facts read-only and prints a path decision summary.
Writes a facts file to \$(mtk_cache_dir)/device-facts-<class>-<serial>-<ts>.txt

  --serial <serial>          Target a specific device (required if >1 attached)
  --explain-classification   Show why the device classified as it did, then exit
  --help                     This text

Environment:
  MTK_ROOT_FIXTURE=<dir>     Read from fixture files instead of a device (tests)
EOF
  exit 0
}

# ---------------------------------------------------------------------------
# Unlock / lock signal interpretation
# ---------------------------------------------------------------------------

# carrier_lock_verdict
#
# Deliberately hardcoded to UNDETERMINED. There is no read-only property that
# distinguishes "carrier-locked" from "the OEM unlocking toggle is simply off":
#   - sys.oem_unlock_allowed mirrors the toggle, so it reads empty/0 in both cases
#   - ro.oem_unlock_supported is not populated on Pixel devices at all
#   - settings get global oem_unlock_allowed is null until the toggle is used
# Printing a negative here would wrongly rule out a whole path, so the script
# reports the raw signals and refuses to draw the conclusion.
carrier_lock_verdict() {
  printf 'UNDETERMINED'
}

read_unlock_signals() {
  UNLOCK_FLASH_LOCKED="$(dev_getprop ro.boot.flash.locked)"
  UNLOCK_VBSTATE="$(dev_getprop ro.boot.verifiedbootstate)"
  UNLOCK_DEVICE_STATE="$(dev_getprop ro.boot.vbmeta.device_state)"
  UNLOCK_SYS_ALLOWED="$(dev_getprop sys.oem_unlock_allowed)"
  UNLOCK_OEM_SUPPORTED="$(dev_getprop ro.oem_unlock_supported)"

  UNLOCK_SETTING=""
  if [[ -z ${MTK_ROOT_FIXTURE:-} ]]; then
    UNLOCK_SETTING="$(mtk_adb shell settings get global oem_unlock_allowed 2>/dev/null | tr -d '\r' || true)"
  fi

  # The toggle's own state is the thing that matters for unlockability, and it
  # is precisely the thing that cannot be read reliably. Track it as tri-state.
  case "$UNLOCK_SYS_ALLOWED" in
    1) UNLOCK_TOGGLE="ON" ;;
    0) UNLOCK_TOGGLE="OFF" ;;
    *) UNLOCK_TOGGLE="UNREADABLE" ;;
  esac
}

# ---------------------------------------------------------------------------
# Facts file
# ---------------------------------------------------------------------------

write_facts_file() {
  local out_path="$1"
  local tmp_file="" prop="" value=""

  tmp_file="$(mktemp)"
  # shellcheck disable=SC2064  # expand tmp_file now; it must survive this scope
  trap "rm -f '$tmp_file'" RETURN

  {
    printf '# mtk_root device facts\n'
    printf '# generated: %s\n' "$(date -u '+%Y-%m-%dT%H:%M:%SZ')"
    printf '# serial: %s\n' "$MTK_SERIAL"
    printf '# class: %s\n' "$MTK_DEVICE_CLASS"
    printf '#\n'
    printf '# This file is read by 20-dump-stock.sh, and is the source for the\n'
    printf '# tests/fixtures/ entries. Format is deliberately line-oriented.\n'
    printf '\n[properties]\n'
    for prop in "${FACT_PROPS[@]}"; do
      value="$(dev_getprop "$prop")"
      printf '%s=%s\n' "$prop" "$value"
    done

    printf '\n[settings]\n'
    printf 'global.oem_unlock_allowed=%s\n' "${UNLOCK_SETTING:-}"

    printf '\n[partitions]\n'
    printf 'ab_scheme=%s\n' "$MTK_AB_SCHEME"
    printf 'slot_suffix=%s\n' "${MTK_SLOT_SUFFIX:-}"
    printf 'slot_suffix_assumed=%s\n' "${MTK_SLOT_ASSUMED:-0}"
    printf 'ramdisk_partition=%s\n' "${MTK_RAMDISK_PART:-}"
    printf 'ramdisk_carrier=%s\n' "$(mtk_ramdisk_carrier)"
    printf 'vbmeta_partition=%s\n' "${MTK_VBMETA_PART:-}"

    printf '\n[by-name]\n'
    printf '%s\n' "$MTK_BY_NAME"
  } >"$tmp_file"

  mv "$tmp_file" "$out_path"
  trap - RETURN
  printf '%s' "$out_path"
}

# shellcheck source=lib/recon_report.sh
source "$SCRIPT_DIR/lib/recon_report.sh"

main() {
  printf '\033[1m%s - read-only device recon\033[0m\n' "$SCRIPT_NAME"

  if ! mtk_select_device "$REQUESTED_SERIAL"; then
    exit 1
  fi

  # Before any getprop: an unauthorized device answers every property query
  # with an empty string, which is indistinguishable from "device has no such
  # property" and would produce a confidently wrong report.
  if ! mtk_require_authorized; then
    exit 1
  fi

  mtk_info "Target: ${MTK_SERIAL}"

  classify_device

  if [[ $EXPLAIN_ONLY -eq 1 ]]; then
    mtk_explain_classification
    exit 0
  fi

  mtk_heading "Identity"
  printf '  serial          : %s\n' "$MTK_SERIAL"
  printf '  manufacturer    : %s\n' "${MTK_PROP_MANUFACTURER:-<unset>}"
  printf '  model           : %s\n' "${MTK_PROP_MODEL:-<unset>}"
  printf '  platform        : %s / %s\n' "${MTK_PROP_PLATFORM:-<unset>}" "${MTK_PROP_HARDWARE:-<unset>}"
  printf '  classified as   : %s\n' "$MTK_DEVICE_CLASS"
  printf '  because         : %s\n' "$MTK_CLASS_REASON"

  if [[ $MTK_DEVICE_CLASS == "UNKNOWN" ]]; then
    mtk_error "Device did not match any known profile - refusing to report a path."
    report_decision
    exit 1
  fi

  if ! discover_partitions; then
    mtk_error "Could not read /dev/block/by-name/ - no partition facts available."
    mtk_error "On most devices that listing needs no root; if it is empty, the"
    mtk_error "device may be in an unusual state. Do not flash anything."
    exit 1
  fi

  read_unlock_signals

  report_partitions
  report_lock_state
  report_manual_checks

  local cache_dir="" facts_path=""
  cache_dir="$(mtk_cache_dir)"
  mkdir -p "$cache_dir"
  facts_path="${cache_dir}/device-facts-${MTK_DEVICE_CLASS}-${MTK_SERIAL}-$(date -u '+%Y%m%dT%H%M%SZ').txt"
  write_facts_file "$facts_path" >/dev/null

  report_decision

  mtk_heading "Facts file"
  printf '  %s\n' "$facts_path"
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --serial)
      [[ $# -ge 2 ]] || {
        mtk_error "--serial needs a value"
        exit 1
      }
      REQUESTED_SERIAL="$2"
      shift 2
      ;;
    --explain-classification)
      EXPLAIN_ONLY=1
      shift
      ;;
    -h | --help) usage ;;
    *)
      mtk_error "Unknown option: $1"
      exit 1
      ;;
  esac
done

main