#!/usr/bin/env bash
# OpenBao source backend for render-secrets.sh. Sourced, never run directly.
#
# Functions:
#   thermograph_openbao_source <env>                 -> merged dotenv on STDOUT
#   thermograph_render_openbao  <env> <out>          -> source, then write <out>
#   thermograph_render_openbao_centralis <env> [out] -> quoted /etc/centralis.env
#
# The first two serve the app stack (/etc/thermograph.env, raw unquoted dotenv). The
# third serves Centralis, whose file is SOURCED by bash and therefore single-quoted —
# a different shape for a different consumer, not an inconsistency.
#
# render_thermograph_secrets in render-secrets.sh dispatches to the second when
# TG_SECRETS_BACKEND=openbao, and is otherwise completely untouched — so the SOPS path
# keeps byte-identical behaviour and all new risk is confined to this file. See the
# note above thermograph_render_openbao on why the write path is duplicated here
# rather than shared, and when to consolidate.
#
# WHY OUTPUT SHAPE IS FROZEN: /etc/thermograph.env must stay raw, UNQUOTED KEY=value.
# Centralis' secrets_inventory / secrets_render compare that file textually
# (deploy/secrets/README.md:206-210), compose reads it via `env_file:`, and the Swarm
# stack's env-entrypoint.sh parses it line by line. Quoting it "properly" would be an
# improvement in isolation and a silent break in context.

# thermograph_openbao_source <env_name>
#
# Reads the common set then the per-environment set and merges them with the
# environment winning — the same last-wins semantic as the SOPS concatenation, except
# performed explicitly here because OpenBao returns a map per path rather than a
# stream that can simply be appended.
thermograph_openbao_source() {
  local env_name="${1:?env name required}"
  local addr="${THERMOGRAPH_BAO_ADDR:-https://10.10.0.1:8200}"
  local mount="${THERMOGRAPH_BAO_MOUNT:-thermograph}"
  # Explicit override first, then the per-environment value env-topology.sh derives,
  # then the conventional path. Same precedence shape as render-secrets.sh:44's
  # THERMOGRAPH_SECRETS_BACKEND / TG_SECRETS_BACKEND pair, for the same reason: the
  # THERMOGRAPH_-prefixed name is the by-hand escape hatch, the TG_ one is what the
  # deploy path sets. Falling straight through to the bare default is what made beta
  # authenticate as tg-prod and get denied its own path.
  local approle="${THERMOGRAPH_BAO_APPROLE:-${TG_BAO_APPROLE:-/etc/thermograph/openbao-approle}}"
  local ca="${THERMOGRAPH_BAO_CACERT:-/etc/thermograph/openbao-ca.crt}"

  command -v bao >/dev/null 2>&1 || {
    echo "!! bao CLI not installed but this host is configured for the openbao backend" >&2
    return 1
  }
  command -v python3 >/dev/null 2>&1 || {
    echo "!! python3 required to render dotenv from OpenBao JSON" >&2
    return 1
  }

  # AppRole credentials: role_id and secret_id, one per line, 0400 root — the same
  # protection level as /etc/thermograph/age.key today. Read directly if we can, else
  # via sudo, mirroring how render-secrets.sh lifts the age key.
  local creds
  if [ -r "$approle" ]; then
    creds=$(cat "$approle")
  else
    creds=$(sudo cat "$approle" 2>/dev/null || true)
  fi
  [ -n "$creds" ] || {
    echo "!! cannot read OpenBao AppRole credentials at $approle (need sudo)" >&2
    return 1
  }

  local role_id secret_id
  role_id=$(printf '%s\n' "$creds" | sed -n '1p')
  secret_id=$(printf '%s\n' "$creds" | sed -n '2p')
  [ -n "$role_id" ] && [ -n "$secret_id" ] || {
    echo "!! $approle malformed: expected role_id on line 1, secret_id on line 2" >&2
    return 1
  }

  export BAO_ADDR="$addr"
  [ -f "$ca" ] && export BAO_CACERT="$ca"

  # Exchange the AppRole for a short-lived token. The token TTL is set on the role
  # (see bootstrap.sh) and is deliberately measured in minutes: it only has to
  # outlive one render.
  local token
  token=$(bao write -field=token auth/approle/login \
            role_id="$role_id" secret_id="$secret_id" 2>/dev/null) || {
    echo "!! OpenBao AppRole login failed for env='${env_name}'" >&2
    echo "!! check that OpenBao at $addr is reachable and UNSEALED" >&2
    return 1
  }
  export BAO_TOKEN="$token"

  # Fetch. `common` is skipped for dev by the same flag the SOPS path uses — but note
  # that on the OpenBao path the flag is belt, not braces: dev's AppRole is bound to
  # the tg-host-dev policy, which DENIES thermograph/data/common outright. If this
  # flag is ever forgotten at a call site, dev gets a 403 rather than a file full of
  # production credentials. That inversion — from "the caller must remember" to "the
  # store refuses" — is the main reason for this migration.
  local common_json="" env_json
  if [ "${THERMOGRAPH_SECRETS_SKIP_COMMON:-0}" != 1 ]; then
    common_json=$(bao kv get -format=json -mount="$mount" common 2>/dev/null) || {
      echo "!! cannot read ${mount}/common for env='${env_name}'" >&2
      echo "!! if this is dev, THERMOGRAPH_SECRETS_SKIP_COMMON=1 was not set and the" >&2
      echo "!! tg-host-dev policy correctly refused — that is the guard working." >&2
      return 1
    }
  fi

  env_json=$(bao kv get -format=json -mount="$mount" "env/${env_name}" 2>/dev/null) || {
    echo "!! cannot read ${mount}/env/${env_name}" >&2
    return 1
  }

  # Merge and emit. Python rather than jq because jq is not installed on these hosts
  # and python3 is (the Centralis renderer already relies on it).
  #
  # This step also enforces the two invariants the dotenv format cannot express:
  #   * a value containing a newline is REJECTED, because it would silently become
  #     two lines and the second would parse as a bogus KEY=value or be dropped;
  #   * a value containing a shell metacharacter is REJECTED, because
  #     /etc/thermograph.env is sourced by bash in six places (deploy.sh:133,
  #     deploy-stack.sh:98, both daemon entrypoints, ops-cron.yml:85, terraform), so
  #     `$(...)` or a backtick in a secret is a live command-execution path on the
  #     deploy host. Refusing here turns a latent code-execution bug into a loud
  #     render failure.
  #
  #     An earlier version of this comment claimed the SOPS path had never tripped
  #     this "only because every current value happens to be alphanumeric". That is
  #     false: CENTRALIS_TOKENS is JSON and full of double quotes. It has never
  #     tripped THESE paths because it is not in them — it lives at
  #     centralis/<env> and renders to /etc/centralis.env, which is single-quoted
  #     precisely because raw dotenv cannot carry it. See
  #     thermograph_render_openbao_centralis at the end of this file.
  THERMOGRAPH_BAO_COMMON="$common_json" \
  THERMOGRAPH_BAO_ENV="$env_json" \
  python3 - <<'PY'
import json, os, re, sys

def load(raw):
    if not raw:
        return {}
    doc = json.loads(raw)
    return doc.get("data", {}).get("data", {}) or {}

merged = {}
# common first, environment second: last-wins, matching the SOPS concatenation order.
for src in ("THERMOGRAPH_BAO_COMMON", "THERMOGRAPH_BAO_ENV"):
    merged.update(load(os.environ.get(src, "")))

KEY_RE = re.compile(r"^[A-Za-z_][A-Za-z0-9_]*$")
# Characters that change meaning when the file is sourced by bash.
UNSAFE = set("`$\\\"'")

bad = []
lines = []
# Validate EVERYTHING before emitting a single byte. Printing as we go would leave
# partial output on stdout when a later key fails, and render-secrets.sh's whole
# discipline is that a failed source never produces a partial env file.
for key in sorted(merged):
    if not KEY_RE.match(key):
        bad.append(f"{key}: not a valid env var name")
        continue
    val = merged[key]
    if val is None:
        val = ""
    if not isinstance(val, str):
        val = json.dumps(val, separators=(",", ":"))
    if "\n" in val or "\r" in val:
        bad.append(f"{key}: value contains a newline (would corrupt the dotenv)")
        continue
    if UNSAFE & set(val):
        bad.append(
            f"{key}: value contains a shell metacharacter (one of ` $ \\ \" ') and "
            f"/etc/thermograph.env is sourced by bash — refusing"
        )
        continue
    lines.append(f"{key}={val}")

if bad:
    sys.stderr.write("!! refusing to render; unsafe values:\n")
    for line in bad:
        sys.stderr.write(f"!!   {line}\n")
    sys.exit(1)

if not lines:
    sys.stderr.write("!! refusing to render: OpenBao returned zero keys\n")
    sys.exit(1)

sys.stdout.write("\n".join(lines) + "\n")
PY
}

# thermograph_render_openbao <env_name> <out_file>
#
# The OpenBao equivalent of render_thermograph_secrets: source, then write.
#
# ON THE DUPLICATED WRITE PATH. The write logic below mirrors
# render-secrets.sh:130-154 rather than being factored out and shared. That is a
# deliberate, temporary choice, not an oversight:
#
#   render-secrets.sh is on the deploy path for all three environments and there is no
#   test suite in front of it (infra/CLAUDE.md: "Shell here runs as root over SSH
#   against live hosts with no test suite in front of it"). Extracting the write path
#   would mean the SOPS render — which currently works — starts flowing through newly
#   moved code that cannot be tested end-to-end from here. An early-return branch keeps
#   the SOPS path byte-identical and confines all new risk to the new backend.
#
#   CONSOLIDATE THESE after prod has been on the OpenBao backend for a full release
#   cycle and the SOPS path is being deleted anyway. Until then, a change to one write
#   path must be made in both — which is exactly the cost being accepted here.
thermograph_render_openbao() {
  local env_name="${1:?env name required}"
  local out="${2:?output path required}"

  echo "==> Rendering $out from OpenBao (env=${env_name})"

  local tmp; tmp=$(mktemp)
  # Holds DECRYPTED secrets. Removed on every exit path. Deliberately not a
  # `trap ... RETURN` — see render-secrets.sh:82-91 for why that is actively wrong in
  # a sourced function (the trap persists into the caller and re-fires on its next
  # `source`, where the local is unset and `set -u` makes it fatal and silent).
  if ! thermograph_openbao_source "$env_name" > "$tmp"; then
    rm -f "$tmp"
    return 1
  fi

  # An empty render must never reach $out. The source function already refuses a
  # zero-key result, so this is a second line of defence rather than the only one:
  # a truncated /etc/thermograph.env is the single worst outcome available here,
  # because thermograph.service uses `EnvironmentFile=-` (missing is NOT fatal) and
  # the app self-generates AUTH_SECRET and the VAPID pair when they are absent. The
  # result would be a green deploy that silently invalidated every session and
  # deleted every push subscription.
  if [ ! -s "$tmp" ]; then
    echo "!! OpenBao render produced an empty file; refusing to write $out" >&2
    rm -f "$tmp"
    return 1
  fi

  local rc=0
  if [ -f "$out" ] && [ -w "$out" ]; then
    cat "$tmp" > "$out" || rc=1
  elif install -m 0640 "$tmp" "$out" 2>/dev/null; then :
  elif sudo install -m 0640 -o "$(id -un)" -g "$(id -gn)" "$tmp" "$out" 2>/dev/null; then :
  else
    echo "!! cannot write $out (need file write access or passwordless sudo)" >&2
    rc=1
  fi

  if [ "$rc" = 0 ] && [ -n "${THERMOGRAPH_SECRETS_ENV_FILE_MIRROR:-}" ]; then
    if ! mkdir -p "$(dirname "$THERMOGRAPH_SECRETS_ENV_FILE_MIRROR")" \
       || ! install -m 0600 "$tmp" "$THERMOGRAPH_SECRETS_ENV_FILE_MIRROR"; then
      echo "!! cannot write mirror at $THERMOGRAPH_SECRETS_ENV_FILE_MIRROR" >&2
      rc=1
    fi
  fi

  rm -f "$tmp"
  return "$rc"
}

# ---------------------------------------------------------------------------
# CENTRALIS
# ---------------------------------------------------------------------------
# /etc/centralis.env is a different file, with a different consumer, and therefore a
# different output shape. render-secrets.sh:206-233 carries the full argument; the
# short version is that it is consumed by exactly one thing and that thing is a shell:
#
#     sudo bash -c 'set -a && . /etc/centralis.env && set +a && docker compose up'
#
# `set -a; . file` runs every line through bash's whole expansion pipeline — quote
# removal, parameter expansion, command substitution, field splitting. Raw dotenv is
# therefore not a safe representation here. CENTRALIS_TOKENS is JSON: rendered
# unquoted, bash strips its quotes, and Centralis fails CLOSED on the malformed result
# by serving a single `shared` identity — indistinguishable from the file never having
# been written. That is the 2026-07-24 incident. So this path emits POSIX
# single-quoted assignments and PROVES them by sourcing the result in a clean shell
# before anything touches $dest.
#
# This mirrors render_centralis_secrets rather than sharing with it, for the same
# reason given above thermograph_render_openbao: the SOPS path stays byte-identical
# and all new risk stays in this file. Consolidate the two when the SOPS path is being
# deleted anyway, not before.

# _thermograph_openbao_login <approle_file> <addr> <ca>  -> token on STDOUT
#
# Separate from the login inline in thermograph_openbao_source deliberately: that
# function is now exercised by prod and beta parity and is left untouched.
_thermograph_openbao_login() {
  local approle="$1" addr="$2" ca="$3"
  local creds role_id secret_id
  if [ -r "$approle" ]; then
    creds=$(cat "$approle")
  else
    creds=$(sudo cat "$approle" 2>/dev/null || true)
  fi
  [ -n "$creds" ] || {
    echo "!! cannot read OpenBao AppRole credentials at $approle (need sudo)" >&2
    return 1
  }
  role_id=$(printf '%s\n' "$creds" | sed -n '1p')
  secret_id=$(printf '%s\n' "$creds" | sed -n '2p')
  [ -n "$role_id" ] && [ -n "$secret_id" ] || {
    echo "!! $approle malformed: expected role_id on line 1, secret_id on line 2" >&2
    return 1
  }
  export BAO_ADDR="$addr"
  [ -f "$ca" ] && export BAO_CACERT="$ca"
  bao write -field=token auth/approle/login \
    role_id="$role_id" secret_id="$secret_id" 2>/dev/null
}

# thermograph_render_openbao_centralis <env_name> [dest]
thermograph_render_openbao_centralis() {
  local env_name="${1:?env name required}"
  local dest="${2:-${CENTRALIS_RENDER_DEST:-/etc/centralis.env}}"
  local addr="${THERMOGRAPH_BAO_ADDR:-https://10.10.0.1:8200}"
  local mount="${THERMOGRAPH_BAO_MOUNT:-thermograph}"
  local ca="${THERMOGRAPH_BAO_CACERT:-/etc/thermograph/openbao-ca.crt}"
  local approle="${THERMOGRAPH_BAO_CENTRALIS_APPROLE:-/etc/thermograph/openbao-approle-centralis}"

  command -v bao >/dev/null 2>&1 || {
    echo "!! bao CLI not installed but this host is configured for the openbao backend" >&2
    return 1
  }
  command -v python3 >/dev/null 2>&1 || {
    echo "!! python3 not installed; needed to quote values safely for a sourced file" >&2
    return 1
  }

  echo "==> Rendering ${dest} from OpenBao (${mount}/centralis/${env_name})"

  local token
  token=$(_thermograph_openbao_login "$approle" "$addr" "$ca") || return 1
  [ -n "$token" ] || {
    echo "!! OpenBao AppRole login failed for centralis" >&2
    echo "!! check that OpenBao at $addr is reachable and UNSEALED" >&2
    return 1
  }
  export BAO_TOKEN="$token"

  # ONE 0700 temp directory holding plaintext, so cleanup is a single rm on every
  # path. Deliberately not a `trap ... RETURN`: this file is SOURCED, and such a trap
  # persists into the caller's shell and re-fires on its next `source`.
  local work rc=0
  work=$(mktemp -d) || { echo "!! mktemp -d failed" >&2; return 1; }
  chmod 700 "$work"

  # Subshell so no failure path can skip the cleanup, and so umask cannot leak out.
  # Every step carries its own `|| exit 1`: `set -e` is DISABLED inside a compound
  # command that is the left operand of `||`, which this subshell is.
  (
    umask 077

    bao kv get -format=json -mount="$mount" "centralis/${env_name}" \
      > "$work/kv.json" 2>/dev/null || {
      echo "!! cannot read ${mount}/centralis/${env_name}" >&2
      exit 1
    }

    python3 - "$work/kv.json" "$work/plain.json" <<'UNWRAP' || exit 1
import json, sys
doc = json.load(open(sys.argv[1], encoding="utf-8"))
data = doc.get("data", {}).get("data", {}) or {}
if not data:
    sys.stderr.write("!! OpenBao returned zero keys for centralis\n")
    sys.exit(1)
json.dump(data, open(sys.argv[2], "w", encoding="utf-8"))
UNWRAP

    python3 - "$work/plain.json" "$work/out.env" "$work/want.json" <<'EMIT' || exit 1
import json, re, sys

src, out_env, want_json = sys.argv[1], sys.argv[2], sys.argv[3]
NAME = re.compile(r"[A-Za-z_][A-Za-z0-9_]*\Z")


def shell_quote(v):
    """POSIX single-quoting. Inside '...' every byte is literal except ' itself,
    which is closed, backslash-escaped and reopened. There is no escape sequence
    to get wrong and no character class to keep up to date: it is total, and
    total is the only property worth having for a file bash will expand."""
    return "'" + v.replace("'", "'\\''") + "'"


def scalar(k, v):
    if isinstance(v, str):
        return v
    if isinstance(v, bool):          # before int: bool is an int in Python
        return "true" if v else "false"
    if isinstance(v, (int, float)):
        return json.dumps(v)
    if v is None:
        return ""
    sys.stderr.write(
        "!! %s is a %s, but an env file holds only scalars\n" % (k, type(v).__name__))
    sys.exit(1)


data = json.load(open(src, encoding="utf-8"))
want, lines = {}, []
for k, v in data.items():
    if not NAME.match(k):
        sys.stderr.write("!! %r is not a usable shell variable name\n" % (k,))
        sys.exit(1)
    want[k] = scalar(k, v)
    lines.append("%s=%s\n" % (k, shell_quote(want[k])))

with open(out_env, "w", encoding="utf-8") as fh:
    fh.write("# Rendered by infra/deploy/render-secrets-openbao.sh from OpenBao.\n")
    fh.write("# DO NOT EDIT BY HAND: the next render overwrites this file, and a\n")
    fh.write("# hand-edit is how the token registry was lost on 2026-07-24.\n")
    fh.write("# Rotate with `bao kv put` against thermograph/centralis/<env> instead.\n")
    fh.writelines(lines)
with open(want_json, "w", encoding="utf-8") as fh:
    json.dump(want, fh)
sys.stderr.write("    %d keys quoted\n" % len(want))
EMIT

    # PROVE IT. Source the rendered file exactly the way the deploy does — clean
    # environment, `set -a`, nothing inherited that could mask a dropped key — and
    # read every value back. This is the check the 2026-07-24 file could not pass.
    # shellcheck disable=SC2016  # single quotes are the point: "$1" must be expanded
    # by the inner `bash -c` against the argument after `_`, not by this shell.
    env -i PATH="$PATH" bash -c \
      'set -a; . "$1"; set +a; exec python3 -c "
import json, os, sys
sys.stdout.write(json.dumps(dict(os.environ)))"' _ "$work/out.env" \
      > "$work/got.json" || exit 1

    python3 - "$work/want.json" "$work/got.json" <<'VERIFY' || exit 1
import json, sys

want = json.load(open(sys.argv[1], encoding="utf-8"))
got = json.load(open(sys.argv[2], encoding="utf-8"))

bad = []
for k, v in want.items():
    if k not in got:
        bad.append("%s: not set at all after sourcing" % k)
    elif got[k] != v:
        # NEVER print either value. The difference is the finding; the content is
        # not, and this runs inside a deploy log.
        bad.append("%s: survives sourcing as a DIFFERENT value (len %d -> %d)"
                   % (k, len(v), len(got[k])))
if bad:
    sys.stderr.write("!! the rendered file does not round-trip through bash:\n")
    for b in bad:
        sys.stderr.write("!!   %s\n" % b)
    sys.exit(1)

# CENTRALIS_TOKENS is the reason for all of the above: JSON, full of double quotes,
# in a file bash expands. Centralis fails CLOSED on malformed JSON — it drops to the
# single `shared` identity, which looks exactly like the registry never having been
# configured. Refuse to write a file that would do that.
raw = got.get("CENTRALIS_TOKENS", "")
if raw:
    try:
        reg = json.loads(raw)
    except ValueError as exc:
        sys.stderr.write("!! CENTRALIS_TOKENS is not valid JSON after sourcing: %s\n" % exc)
        sys.exit(1)
    if not isinstance(reg, dict) or not reg:
        sys.stderr.write("!! CENTRALIS_TOKENS must be a non-empty JSON object\n")
        sys.exit(1)
    if not all(isinstance(s, str) and isinstance(t, str) and t for s, t in reg.items()):
        sys.stderr.write("!! CENTRALIS_TOKENS must map subject -> non-empty token string\n")
        sys.exit(1)
    # Subjects are names on audit lines, not credentials. Printing them is the whole
    # point: it is how an operator sees at a glance that nobody was lost.
    sys.stderr.write("    CENTRALIS_TOKENS parses: %d subject(s) — %s\n"
                     % (len(reg), ", ".join(sorted(reg))))

sys.stderr.write("    %d keys survive `set -a; . <file>` byte-for-byte\n" % len(want))
VERIFY
  ) || rc=1

  # Only now, with a file read back through bash and matched value for value, does
  # anything touch $dest. 0600: four bearer credentials for the estate's control
  # plane, with no group that needs them.
  if [ "$rc" -eq 0 ]; then
    if [ -f "$dest" ] && [ -w "$dest" ]; then
      cat "$work/out.env" > "$dest" || rc=1
    elif install -m 0600 "$work/out.env" "$dest" 2>/dev/null; then :
    elif sudo install -m 0600 -o "$(id -un)" -g "$(id -gn)" "$work/out.env" "$dest" 2>/dev/null; then :
    else
      echo "!! cannot write ${dest} (need file write access or passwordless sudo)" >&2
      rc=1
    fi
  else
    echo "!! render aborted; ${dest} left untouched" >&2
  fi

  rm -rf "$work"
  return "$rc"
}