#!/bin/bash
# minimax init — write ~/.claude/settings.json with apiKeyHelper.
#
# The MiniMax API key is mounted by ESO at /run/agent/secrets/minimax/api_key
# (mode 0400, secrets_required entry in harness.yaml). Claude Code's
# `apiKeyHelper` setting names a command that prints the key on stdout when
# the CLI needs it for an API request — the value never enters this process'
# environment, never appears in /proc/<pid>/environ of the claude subprocess,
# and is read fresh on each invocation so ESO secret rotations are picked up
# without a process restart.
#
# Why settings.json (not --settings inline or env vars):
#  - ANTHROPIC_AUTH_TOKEN / ANTHROPIC_API_KEY in env exposes the secret in
#    /proc/<pid>/environ, log aggregators, ps. The H-SECRET-4 rule disallows
#    credential-shaped env vars for that reason.
#  - --settings on the runner CLI line couples the runner to the harness
#    layout. Per-harness settings.json keeps auth a harness concern.
#  - The helper command (`cat <file>`) re-reads on each call, so secret
#    rotation propagates without rewriting the config file.

set -euo pipefail

API_KEY_FILE="/run/agent/secrets/minimax/api_key"

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

# init.sh runs as root in uid-wrapper.sh BEFORE gosu drops privileges to the
# agent user — so $HOME here is /root, not the agent home. Claude Code will
# run as the agent user and read its config from $AGENT_HOME/.claude. Resolve
# the agent home explicitly so settings.json lands where claude looks.
AGENT_USER="${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

# CLAUDE_CONFIG_DIR overrides ~/.claude when set.
CONFIG_DIR="${CLAUDE_CONFIG_DIR:-$AGENT_HOME/.claude}"
mkdir -p "$CONFIG_DIR"
chown "$AGENT_USER:" "$CONFIG_DIR" 2>/dev/null || true
chmod 0755 "$CONFIG_DIR"

SETTINGS_FILE="$CONFIG_DIR/settings.json"

# If a settings.json already exists from another harness layer, merge
# apiKeyHelper into it; otherwise create a minimal file. jq is in the base
# image; fall back to a clean overwrite if it isn't available for any reason.
if [ -f "$SETTINGS_FILE" ] && command -v jq >/dev/null 2>&1; then
    TMP=$(mktemp)
    jq --arg helper "cat $API_KEY_FILE" \
       '. + {apiKeyHelper: $helper}' \
       "$SETTINGS_FILE" > "$TMP"
    mv "$TMP" "$SETTINGS_FILE"
else
    cat > "$SETTINGS_FILE" <<EOF
{
  "apiKeyHelper": "cat $API_KEY_FILE"
}
EOF
fi

# settings.json holds the helper command (a path), not a credential value.
# It must be readable by the agent user that runs claude.
chown "$AGENT_USER:" "$SETTINGS_FILE" 2>/dev/null || true
chmod 0644 "$SETTINGS_FILE"
echo "minimax api_key wired via apiKeyHelper at $SETTINGS_FILE (agent_user=$AGENT_USER)"