#!/usr/bin/env bash
#
# bf-enrollment-status - read-only canonical Field OS lifecycle view.
#
# Lifecycle contract (docs/29-DEVICE-ENROLLMENT.md, provisioning/enrollment/README.md):
#
#   PROVISIONED_OFFLINE  local (offline) provisioning is complete. No internet,
#                        no central record and no WireGuard handshake is needed
#                        or claimed at this stage.
#   ENROLLED             central accepted the device, a WireGuard peer was
#                        assigned and monitoring/inventory/remote access
#                        configuration is applied (or being applied).
#   READY                local health plus every central channel (monitoring,
#                        remote, management) is verified.
#
#   Transitions are forward-only and never skip a stage:
#     (none) -> PROVISIONED_OFFLINE -> ENROLLED -> READY
#   A missing stage, a backwards move, or READY without verified central
#   evidence is reported as INVALID and exits non-zero (fail closed).
#
# State file: ${BF_STATE_FILE:-/var/lib/blueforce/state.json}
#   mode 0600; fields phase, enrollment_status, fleet_status, device_id,
#   provisioning_id. Unknown extra fields are preserved by writers and ignored
#   here.
#
# Output vocabulary (stable, consumed by bf-status/bf-check-*):
#   Lifecycle  : PROVISIONED_OFFLINE | ENROLLED | READY | PENDING | INVALID
#   Enrollment : PENDING | ENROLLED | COMPLETE
#   Fleet      : PENDING | NOT_READY | READY
#
# Exit status: 0 lifecycle valid, 1 missing/invalid state, 2 usage error.
# Never writes anything and never prints secrets.
#
set -euo pipefail

STATE_FILE="${BF_STATE_FILE:-${STATE_DIR:-/var/lib/blueforce}/state.json}"
# Canonical lifecycle phases; the order in this list is the only legal order.
VALID_STATES='PROVISIONED_OFFLINE ENROLLED READY'
FIELD='all'

usage() {
    cat <<'EOF'
Usage: bf-enrollment-status [--field phase|enrollment|fleet] [--check]

Print the canonical Field OS lifecycle state (read-only, no secrets).

Options:
  --field NAME   print one bare value instead of the three-line report
                 (NAME is phase, enrollment or fleet)
  --check        accepted for symmetry with the installer modules; this
                 command never mutates anything
  --help         show this help

Exit status: 0 valid lifecycle, 1 missing or contract-violating state,
2 usage error.

Lifecycle vocabulary : PROVISIONED_OFFLINE | ENROLLED | READY | PENDING | INVALID
Enrollment vocabulary: PENDING | ENROLLED | COMPLETE
Fleet vocabulary     : PENDING | NOT_READY | READY

Forward-only transitions: PROVISIONED_OFFLINE -> ENROLLED -> READY.
EOF
}

if [[ "${1:-}" == '--help' || "${1:-}" == '-h' ]]; then
    usage
    exit 0
fi
while [[ $# -gt 0 ]]; do
    case "$1" in
        --field)
            [[ $# -ge 2 ]] || { echo 'ERROR: --field needs a value' >&2; exit 2; }
            FIELD="$2"
            shift 2
            ;;
        --check)
            shift
            ;;
        *)
            echo "ERROR: unknown argument: $1" >&2
            usage >&2
            exit 2
            ;;
    esac
done
case "$FIELD" in
    all|phase|enrollment|fleet) ;;
    *) echo "ERROR: --field must be phase, enrollment or fleet (got: $FIELD)" >&2; exit 2 ;;
esac

if [[ ! -r "$STATE_FILE" ]]; then
    # No lifecycle state yet: the device has not completed offline provisioning.
    if [[ "$FIELD" == 'all' ]]; then
        printf 'Lifecycle: PENDING\nEnrollment: PENDING\nFleet: PENDING\n'
    else
        printf 'PENDING\n'
    fi
    exit 1
fi

python3 - "$STATE_FILE" "$FIELD" <<'PY'
import json
import os
import re
import stat
import sys

path, field = sys.argv[1], sys.argv[2]
VALID_STATES = ('PROVISIONED_OFFLINE', 'ENROLLED', 'READY')
VALID_ENROLLMENT = ('PENDING', 'ENROLLED', 'COMPLETE')
VALID_FLEET = ('PENDING', 'NOT_READY', 'READY')
CHANNELS = ('monitoring', 'remote', 'management')
DEVICE_ID = re.compile(r'^BF-[0-9]{8}$')


def invalid(reason):
    sys.stderr.write('INVALID: %s\n' % reason)
    print('INVALID' if field != 'all' else 'Lifecycle: INVALID')
    raise SystemExit(1)


try:
    with open(path, encoding='utf-8') as handle:
        state = json.load(handle)
except OSError as error:
    invalid('state file is unreadable (%s)' % error.__class__.__name__)
except ValueError as error:
    invalid('state file is not valid JSON (%s)' % error.__class__.__name__)
if not isinstance(state, dict):
    invalid('state file is not a JSON object')

phase = state.get('phase')
if phase not in VALID_STATES:
    invalid('phase is missing or not one of %s' % ', '.join(VALID_STATES))
enrollment = state.get('enrollment_status')
if enrollment not in VALID_ENROLLMENT:
    invalid('enrollment_status is missing or not one of %s' % ', '.join(VALID_ENROLLMENT))
fleet = state.get('fleet_status')
if fleet not in VALID_FLEET:
    invalid('fleet_status is missing or not one of %s' % ', '.join(VALID_FLEET))
device_id = state.get('device_id')
if not isinstance(device_id, str) or not DEVICE_ID.match(device_id):
    invalid('device_id is missing or does not match BF-<8 digits>')
provisioning_id = state.get('provisioning_id')
if not isinstance(provisioning_id, str) or not provisioning_id or len(provisioning_id) > 128 \
        or any(character.isspace() for character in provisioning_id):
    invalid('provisioning_id is missing or malformed')


def evidence_problem(record):
    """Return a reason string when central verification evidence is unusable."""
    if not isinstance(record, dict):
        return 'central_verification is missing'
    if set(record) - {'status', 'verification_id', 'monitoring', 'remote', 'management'}:
        return 'central_verification carries unexpected fields'
    if not {'status', 'verification_id'}.issubset(record):
        return 'central_verification is incomplete'
    if record['status'] not in ('pending', 'verified'):
        return 'central_verification.status is invalid'
    if not isinstance(record['verification_id'], str) or not record['verification_id']:
        return 'central_verification.verification_id is missing'
    for name in CHANNELS:
        item = record.get(name)
        if not isinstance(item, dict) or set(item) != {'status', 'verification_id'}:
            return 'central_verification.%s is missing or malformed' % name
        if item['status'] not in ('pending', 'verified'):
            return 'central_verification.%s.status is invalid' % name
        if not isinstance(item['verification_id'], str) or not item['verification_id']:
            return 'central_verification.%s.verification_id is missing' % name
    return None


record = state.get('central_verification')
problem = evidence_problem(record)

if phase == 'PROVISIONED_OFFLINE':
    if enrollment != 'PENDING':
        invalid('PROVISIONED_OFFLINE requires enrollment_status PENDING (got %s)' % enrollment)
    if fleet == 'READY':
        invalid('PROVISIONED_OFFLINE cannot be fleet READY: a stage was skipped')
    if record is not None:
        sys.stderr.write('WARN: central_verification is present before enrollment\n')
elif phase == 'ENROLLED':
    if enrollment not in ('ENROLLED', 'COMPLETE'):
        invalid('ENROLLED requires enrollment_status ENROLLED or COMPLETE (got %s)' % enrollment)
    if fleet == 'READY':
        invalid('ENROLLED cannot be fleet READY: fleet READY is recorded with phase READY')
    if problem:
        invalid(problem)
elif phase == 'READY':
    if enrollment not in ('ENROLLED', 'COMPLETE'):
        invalid('READY requires a completed enrollment (got %s)' % enrollment)
    if fleet != 'READY':
        invalid('READY requires fleet_status READY (got %s)' % fleet)
    if problem:
        invalid(problem)
    pending = [name for name in CHANNELS if record[name]['status'] != 'verified']
    if record['status'] != 'verified' or pending:
        invalid('READY requires verified central evidence for every channel')

try:
    mode = stat.S_IMODE(os.stat(path).st_mode)
    if mode & 0o077:
        sys.stderr.write('WARN: %s is mode %04o; the lifecycle contract requires 0600\n' % (path, mode))
except OSError:
    pass

# Enrolment is reported as COMPLETE once READY is recorded: both facts come from
# the same forward-only transition chain.
enrollment_display = 'COMPLETE' if (phase == 'READY' or enrollment == 'COMPLETE') else enrollment
fleet_display = 'READY' if fleet == 'READY' else 'NOT READY'

if field == 'phase':
    print(phase)
elif field == 'enrollment':
    print(enrollment_display)
elif field == 'fleet':
    print(fleet_display)
else:
    print('Lifecycle: ' + phase)
    print('Enrollment: ' + enrollment_display)
    print('Fleet: ' + fleet_display)
PY