#!/bin/bash
# Machine registry logic

MACHINES_FILE="${DATA_DIR:-/data/fleet}/machines.json"
STALE_THRESHOLD=60  # seconds

# Get current timestamp
now() {
    date +%s
}

# Read machines file with lock
read_machines() {
    if [ -f "$MACHINES_FILE" ]; then
        cat "$MACHINES_FILE"
    else
        echo '{}'
    fi
}

# Write machines file with lock
write_machines() {
    local data="$1"
    echo "$data" > "$MACHINES_FILE.tmp"
    mv "$MACHINES_FILE.tmp" "$MACHINES_FILE"
}

# Update machine status based on lastSeen
update_status() {
    local machines="$1"
    local current_time=$(now)

    echo "$machines" | jq --arg now "$current_time" --arg threshold "$STALE_THRESHOLD" '
        to_entries | map(
            .value.status = (
                if (.value.lastSeen | tonumber) < (($now | tonumber) - ($threshold | tonumber))
                then "unknown"
                else .value.status
                end
            )
        ) | from_entries
    '
}

# Handle POST /api/machines/register
handle_register() {
    local body="$1"

    # Validate JSON
    if ! echo "$body" | jq -e . >/dev/null 2>&1; then
        send_error "400 Bad Request" "Invalid JSON"
        return
    fi

    # Extract required fields
    local id=$(echo "$body" | jq -r '.id // empty')
    local name=$(echo "$body" | jq -r '.name // empty')
    local url=$(echo "$body" | jq -r '.url // empty')

    if [ -z "$id" ] || [ -z "$name" ] || [ -z "$url" ]; then
        send_error "400 Bad Request" "Missing required fields: id, name, url"
        return
    fi

    # Read current machines
    local machines=$(read_machines)
    local current_time=$(now)

    # Create/update machine entry
    local machine=$(echo "$body" | jq --arg ts "$current_time" '. + {lastSeen: ($ts | tonumber)}')

    # Add to machines
    machines=$(echo "$machines" | jq --arg id "$id" --argjson machine "$machine" '.[$id] = $machine')

    # Write back
    write_machines "$machines"

    send_json "200 OK" "$machine"
}

# Handle GET /api/machines
handle_list_machines() {
    local machines=$(read_machines)

    # Update status based on lastSeen
    machines=$(update_status "$machines")

    # Convert to array
    local result=$(echo "$machines" | jq '[to_entries[] | .value]')

    send_json "200 OK" "$result"
}

# Handle GET /api/machines/:id
handle_get_machine() {
    local id="$1"
    local machines=$(read_machines)

    # Update status
    machines=$(update_status "$machines")

    # Get machine
    local machine=$(echo "$machines" | jq --arg id "$id" '.[$id] // null')

    if [ "$machine" = "null" ]; then
        send_error "404 Not Found" "Machine not found"
        return
    fi

    send_json "200 OK" "$machine"
}

# Handle DELETE /api/machines/:id
handle_delete_machine() {
    local id="$1"
    local machines=$(read_machines)

    # Check if exists
    local exists=$(echo "$machines" | jq --arg id "$id" 'has($id)')

    if [ "$exists" = "false" ]; then
        send_error "404 Not Found" "Machine not found"
        return
    fi

    # Remove machine
    machines=$(echo "$machines" | jq --arg id "$id" 'del(.[$id])')
    write_machines "$machines"

    send_json "200 OK" '{"deleted":true}'
}