import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { z } from 'zod';
import { executeCommand } from '../ssh-client.js';
import { SAFE_COMMAND_PREFIXES } from '../constants.js';

export function registerSystemTools(server: McpServer): void {

  // ── rpi_system_status ────────────────────────────────────────────────
  server.registerTool(
    'rpi_system_status',
    {
      title: 'Raspberry Pi System Status',
      description: `Get system resource usage on the Raspberry Pi: CPU load, memory, disk, uptime, and temperature.

Returns a formatted overview of the system health.`,
      inputSchema: {},
      annotations: {
        readOnlyHint: true,
        destructiveHint: false,
        idempotentHint: true,
        openWorldHint: false,
      },
    },
    async () => {
      try {
        const commands = [
          { label: 'Hostname', cmd: 'hostname' },
          { label: 'Uptime', cmd: 'uptime' },
          { label: 'CPU Temperature', cmd: 'cat /sys/class/thermal/thermal_zone0/temp 2>/dev/null || echo "N/A"' },
          { label: 'Memory', cmd: 'free -h | head -3' },
          { label: 'Disk', cmd: 'df -h / | tail -1' },
          { label: 'CPU Load', cmd: 'top -bn1 | head -5' },
        ];

        const sections: string[] = ['# 🖥️ Raspberry Pi System Status\n'];

        for (const { label, cmd } of commands) {
          const result = await executeCommand(cmd);
          let value = result.stdout || 'N/A';

          // Convert CPU temp from millidegrees
          if (label === 'CPU Temperature' && value !== 'N/A') {
            const temp = parseInt(value);
            if (!isNaN(temp)) {
              value = `${(temp / 1000).toFixed(1)}°C`;
            }
          }

          sections.push(`## ${label}\n\`\`\`\n${value}\n\`\`\`\n`);
        }

        return { content: [{ type: 'text', text: sections.join('\n') }] };
      } catch (error) {
        return { content: [{ type: 'text', text: `Error: ${error instanceof Error ? error.message : String(error)}` }] };
      }
    }
  );

  // ── rpi_docker_networks ──────────────────────────────────────────────
  server.registerTool(
    'rpi_docker_networks',
    {
      title: 'List Docker Networks',
      description: `List all Docker networks on the Raspberry Pi with driver and scope info.`,
      inputSchema: {},
      annotations: {
        readOnlyHint: true,
        destructiveHint: false,
        idempotentHint: true,
        openWorldHint: false,
      },
    },
    async () => {
      try {
        const result = await executeCommand('docker network ls --format "table {{.ID}}\t{{.Name}}\t{{.Driver}}\t{{.Scope}}"');

        if (result.code !== 0) {
          return { content: [{ type: 'text', text: `Error: ${result.stderr}` }] };
        }

        return { content: [{ type: 'text', text: `## Docker Networks\n\n\`\`\`\n${result.stdout}\n\`\`\`` }] };
      } catch (error) {
        return { content: [{ type: 'text', text: `Error: ${error instanceof Error ? error.message : String(error)}` }] };
      }
    }
  );

  // ── rpi_run_command ──────────────────────────────────────────────────
  server.registerTool(
    'rpi_run_command',
    {
      title: 'Run Safe Command on RPi',
      description: `Execute a read-only command on the Raspberry Pi via SSH.

Only whitelisted safe commands are allowed (docker ps, docker logs, df, free, uptime, cat, ls, tail, head, grep, etc.).

Args:
  - command (string): The command to execute (must start with a safe prefix)`,
      inputSchema: {
        command: z.string().min(1).max(500).describe('Safe read-only command to execute'),
      },
      annotations: {
        readOnlyHint: true,
        destructiveHint: false,
        idempotentHint: true,
        openWorldHint: true,
      },
    },
    async ({ command }) => {
      try {
        const trimmedCmd = command.trim();
        const isSafe = SAFE_COMMAND_PREFIXES.some(prefix => trimmedCmd.startsWith(prefix));

        if (!isSafe) {
          return {
            content: [{
              type: 'text',
              text: `❌ Command rejected: '${trimmedCmd}' is not in the safe command list.\n\nAllowed prefixes:\n${SAFE_COMMAND_PREFIXES.map(p => `  - ${p}`).join('\n')}`
            }]
          };
        }

        const result = await executeCommand(trimmedCmd);

        const output = result.stdout || result.stderr || '(no output)';
        const status = result.code === 0 ? '✅' : `⚠️ (exit code: ${result.code})`;

        return { content: [{ type: 'text', text: `${status} \`${trimmedCmd}\`\n\n\`\`\`\n${output}\n\`\`\`` }] };
      } catch (error) {
        return { content: [{ type: 'text', text: `Error: ${error instanceof Error ? error.message : String(error)}` }] };
      }
    }
  );
}