#!/bin/bash
# anthropic-cloud-paul-oauth init — write Claude Code's native credentials
# file from the ESO-mounted oauth_token.
#
# Threat model: keep the ESO mount root-only (mode 0400) so the agent user
# cannot directly `cat` /run/agent/secrets/anthropic-cloud-paul-oauth/*.
# init.sh runs as root (in uid-wrapper.sh, before the gosu drop) and writes
# a per-secret artefact at $AGENT_HOME/.claude/.credentials.json with mode
# 0600 owned by agent. Claude Code reads that file natively for OAuth-based
# subscription auth — no env vars, no apiKeyHelper, no wrapper script.
#
# Why .credentials.json (not apiKeyHelper):
#  - This is the SUBSCRIPTION (Pro/Max) path: ENFORCE_SUBSCRIPTION_PRICING=true
#    on this harness causes the runner to strip ANTHROPIC_API_KEY and
#    ANTHROPIC_AUTH_TOKEN from the subprocess env so an accidental API key
#    can't fall through to per-token billing. Subscription auth flows
#    through CLAUDE_CODE_OAUTH_TOKEN — Claude Code's native storage for
#    that is .credentials.json with the claudeAiOauth shape.
#  - apiKeyHelper would still work, but routes through the api_key path,
#    which the runner's subscription-pricing enforcement is specifically
#    designed to block. .credentials.json is the canonical OAuth path.
#
# This mirrors what entrypoint/harness_init.py used to do for the legacy
# SOPS-decrypted CLAUDE_CODE_OAUTH_TOKEN path. Phase 9 ESO-cutover removed
# the SOPS files; this init.sh restores the equivalent behaviour for the
# ESO-mounted token.
#
# Rotation handling: per-container init. Ephemeral container agents (one
# task = one container) always pick up the latest mounted oauth_token.
# Long-running sessions need a future scripts.control_loop hook to
# re-stage between agent CLI invocations.

set -euo pipefail

ESO_OAUTH="/run/agent/secrets/anthropic-cloud-paul-oauth/oauth_token"

if [ ! -r "$ESO_OAUTH" ]; then
    echo "ERROR: $ESO_OAUTH not readable. Check ESO ExternalSecret acct-<anthropic-cloud-paul-oauth-id>." >&2
    exit 1
fi

AGENT_USER="${AGENT_USER:-agent}"
AGENT_HOME=$(getent passwd "$AGENT_USER" | cut -d: -f6)
if [ -z "$AGENT_HOME" ] || [ ! -d "$AGENT_HOME" ]; then
    AGENT_HOME="/home/$AGENT_USER"
fi

CONFIG_DIR="${CLAUDE_CONFIG_DIR:-$AGENT_HOME/.claude}"
mkdir -p "$CONFIG_DIR"
chown "$AGENT_USER:" "$CONFIG_DIR" 2>/dev/null || true
chmod 0700 "$CONFIG_DIR"

# Build the .credentials.json file. The token is piped via stdin so it
# never lands in argv (visible in /proc/<pid>/cmdline) or env. The schema
# matches what `claude setup-token` produces locally and what the legacy
# SOPS path in harness_init.py wrote.
CRED_FILE="$CONFIG_DIR/.credentials.json"
cat "$ESO_OAUTH" | python3 -c "
import json, sys
token = sys.stdin.read().strip()
print(json.dumps({
    'claudeAiOauth': {
        'accessToken': token,
        'refreshToken': None,
        'expiresAt': 4102444800000,
        'scopes': [
            'user:file_upload',
            'user:inference',
            'user:mcp_servers',
            'user:profile',
            'user:sessions:claude_code',
        ],
        'subscriptionType': 'max',
        'rateLimitTier': 'default_claude_max_5x',
    }
}))
" > "$CRED_FILE"

chown "$AGENT_USER:" "$CRED_FILE" 2>/dev/null || true
chmod 0600 "$CRED_FILE"

echo "anthropic-cloud-paul-oauth: oauth_token staged into $CRED_FILE (0600 $AGENT_USER:$AGENT_USER)"