#!/usr/bin/env bash

set -euo pipefail

# bootstrap-detector.sh - Detects if node should bootstrap or join cluster
# Usage: bootstrap-detector.sh [config_file]
#
# Arguments:
#   config_file - Path to cluster-config.json (default: /etc/nixos/secrets/cluster-config.json)
#
# Returns:
#   0 - Node should bootstrap (initialize new cluster)
#   1 - Node should join existing cluster
#   2 - Error (invalid config or missing file)

CONFIG_FILE="${1:-/etc/nixos/secrets/cluster-config.json}"
FIRST_BOOT_MARKER="/var/lib/first-boot-automation/.initialized"

# Logging function with JSON output
log() {
    local level="$1"
    local message="$2"
    local timestamp
    timestamp=$(date -Iseconds)

    echo "{\"timestamp\":\"$timestamp\",\"level\":\"$level\",\"component\":\"bootstrap-detector\",\"message\":\"$message\"}" >&2
}

# Validate config file exists
if [[ ! -f "$CONFIG_FILE" ]]; then
    log "ERROR" "Configuration file not found: $CONFIG_FILE"
    exit 2
fi

# Parse JSON config
log "INFO" "Reading configuration from $CONFIG_FILE"

if ! CONFIG_JSON=$(cat "$CONFIG_FILE"); then
    log "ERROR" "Failed to read configuration file"
    exit 2
fi

# Extract bootstrap flag using jq (fallback to grep if jq not available)
if command -v jq &> /dev/null; then
    BOOTSTRAP=$(echo "$CONFIG_JSON" | jq -r '.bootstrap // false')
    NODE_ID=$(echo "$CONFIG_JSON" | jq -r '.node_id // "unknown"')
    NODE_ROLE=$(echo "$CONFIG_JSON" | jq -r '.node_role // "unknown"')
else
    # Fallback to grep/sed for minimal environments
    BOOTSTRAP=$(echo "$CONFIG_JSON" | grep -Eo '"bootstrap"[[:space:]]*:[[:space:]]*(true|false)' | head -n1 | sed -E 's/.*:[[:space:]]*(true|false)/\1/' || echo "false")
    NODE_ID=$(echo "$CONFIG_JSON" | grep -Eo '"node_id"[[:space:]]*:[[:space:]]*"[^"]+"' | head -n1 | sed -E 's/.*"node_id"[[:space:]]*:[[:space:]]*"([^"]+)".*/\1/' || echo "unknown")
    NODE_ROLE=$(echo "$CONFIG_JSON" | grep -Eo '"node_role"[[:space:]]*:[[:space:]]*"[^"]+"' | head -n1 | sed -E 's/.*"node_role"[[:space:]]*:[[:space:]]*"([^"]+)".*/\1/' || echo "unknown")
fi

log "INFO" "Node configuration: id=$NODE_ID, role=$NODE_ROLE, bootstrap=$BOOTSTRAP"

# Check if this is a reboot (marker file exists)
if [[ -f "$FIRST_BOOT_MARKER" ]]; then
    log "INFO" "First-boot marker found, this is a reboot - skipping cluster join"

    # Read marker info
    if [[ -r "$FIRST_BOOT_MARKER" ]]; then
        MARKER_TIMESTAMP=$(cat "$FIRST_BOOT_MARKER")
        log "INFO" "Node initialized at: $MARKER_TIMESTAMP"
    fi

    # Always join for reboots (clusters should already be initialized)
    exit 1
fi

# First boot logic
log "INFO" "First boot detected (no marker file)"

# Decision based on bootstrap flag
if [[ "$BOOTSTRAP" == "true" ]]; then
    log "INFO" "Bootstrap mode enabled - node will initialize new cluster"

    # Create marker directory and file to track initialization
    mkdir -p "$(dirname "$FIRST_BOOT_MARKER")"
    date -Iseconds > "$FIRST_BOOT_MARKER"

    exit 0  # Bootstrap
else
    log "INFO" "Join mode enabled - node will join existing cluster"

    # Create marker after successful join (done by cluster-join.sh)
    # For now, just return join status
    exit 1  # Join existing
fi