#!/usr/bin/env bash
# bao-session.sh — check, or grant, an OpenBao session an agent session can use.
#
#   ./scripts/bao-session.sh status            what session exists, if any
#   ./scripts/bao-session.sh login             refresh YOUR operator session (OIDC)
#   ./scripts/bao-session.sh grant <task>      mint a scoped, time-boxed token for Claude
#   ./scripts/bao-session.sh revoke            end the granted token immediately
#
# Why `grant` exists
# ------------------
# Handing an agent your own platform-admin session gives it everything you have,
# for as long as you have it, indistinguishable from you in the audit log. The
# grant path instead mints a separate token that is:
#
#   * scoped   — carries the ops-mason-build policy, which can create policies,
#                auth roles and KV *structure* but cannot read secret values.
#                SCOPE.md's "never touch secret values" stops being a promise in
#                a document and becomes something OpenBao enforces.
#   * bounded  — 45 minutes, no renewal past one hour.
#   * named    — display_name claude-<task>, so the audit log says which task an
#                action belonged to, not just that platform-root did it.
#
# It is written to ~/.claude-bao-token, NOT ~/.vault-token, so your own operator
# session is untouched and the two can be revoked independently.
#
# Under WSL2 the OIDC browser launch fails (gio cannot open a browser). This
# script prints the URL plainly and waits, rather than appearing to hang.

set -euo pipefail

export BAO_ADDR="${BAO_ADDR:-https://bao.coulomb.social}"
GRANT_FILE="${GRANT_FILE:-$HOME/.claude-bao-token}"
GRANT_POLICY="${GRANT_POLICY:-ops-mason-build}"
GRANT_TTL="${GRANT_TTL:-45m}"
GRANT_MAX_TTL="${GRANT_MAX_TTL:-1h}"
OIDC_PATH="${OIDC_PATH:-netkingdom}"

green() { printf '\033[32m%s\033[0m\n' "$1"; }
red()   { printf '\033[31m%s\033[0m\n' "$1"; }

describe() {
    # Prints session metadata only. Never the token.
    local token="${1:-}" label="$2"
    local out
    if ! out="$(BAO_TOKEN="$token" bao token lookup -format=json 2>/dev/null)"; then
        red "  $label: none or expired"
        return 1
    fi
    printf '%s' "$out" | python3 -c "
import sys, json
d = json.load(sys.stdin)['data']
print('  $label: ttl=%s policies=%s name=%s' % (
    d.get('ttl'), ','.join(d.get('policies', [])), d.get('display_name') or '-'))
"
}

cmd_status() {
    echo "BAO_ADDR=$BAO_ADDR"
    describe "$(cat "$HOME/.vault-token" 2>/dev/null || true)" "your operator session" || true
    if [[ -f "$GRANT_FILE" ]]; then
        describe "$(cat "$GRANT_FILE")" "granted to Claude " || true
    else
        echo "  granted to Claude : none ($GRANT_FILE absent)"
    fi
}

cmd_login() {
    # No TTY guard: the OIDC flow reads nothing from stdin. It starts a local
    # callback listener, prints a URL, and waits for the browser to complete it,
    # so this works fine from a non-interactive invocation.
    echo "Opening OIDC login. Under WSL2 no browser will launch —"
    echo "copy the URL below into your Windows browser, then come back here."
    echo
    bao login -method=oidc -path="$OIDC_PATH"
    echo
    cmd_status
}

cmd_grant() {
    local task="${1:-}"
    if [[ -z "$task" ]]; then
        red "usage: $0 grant <task-name>   e.g. 'operators-mount'"; exit 2
    fi
    if ! bao policy read "$GRANT_POLICY" >/dev/null 2>&1; then
        red "policy $GRANT_POLICY does not exist yet."
        echo "Create it first — see docs, or ask Claude to draft it. Refusing to"
        echo "fall back to a broader policy: an unscoped grant is the thing this"
        echo "script exists to avoid."
        exit 1
    fi
    umask 077
    bao token create \
        -policy="$GRANT_POLICY" \
        -ttl="$GRANT_TTL" \
        -explicit-max-ttl="$GRANT_MAX_TTL" \
        -display-name="claude-${task}" \
        -field=token > "$GRANT_FILE"
    green "granted: $GRANT_POLICY for '$task', ttl $GRANT_TTL (max $GRANT_MAX_TTL)"
    echo "  file: $GRANT_FILE"
    describe "$(cat "$GRANT_FILE")" "granted to Claude " || true
    echo
    echo "Claude uses it as:  BAO_TOKEN=\$(cat $GRANT_FILE) bao <cmd>"
    echo "Revoke any time:    $0 revoke"
}

cmd_revoke() {
    if [[ ! -f "$GRANT_FILE" ]]; then
        echo "nothing to revoke ($GRANT_FILE absent)"; return 0
    fi
    bao token revoke "$(cat "$GRANT_FILE")" >/dev/null 2>&1 || true
    shred -u "$GRANT_FILE" 2>/dev/null || rm -f "$GRANT_FILE"
    green "granted token revoked and removed"
}

case "${1:-status}" in
    status) cmd_status ;;
    login)  cmd_login ;;
    grant)  shift; cmd_grant "${1:-}" ;;
    revoke) cmd_revoke ;;
    *) echo "usage: $0 status|login|grant <task>|revoke" >&2; exit 2 ;;
esac