import { describe, it, expect, beforeEach } from 'vitest'
import {
  _resetForTest,
  getInstances, getInstance, getDistinctStacks,
  createInstance, updateInstance, deleteInstance, importInstances, getInstanceHistory,
} from '../server/db.js'

beforeEach(() => _resetForTest());

// ── getInstances ──────────────────────────────────────────────────────────────

describe('getInstances', () => {
  it('returns empty array when table is empty', () => {
    expect(getInstances()).toEqual([]);
  });

  it('returns all instances sorted by name', () => {
    createInstance({ name: 'zebra', state: 'deployed', stack: 'production', vmid: 1, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    createInstance({ name: 'alpha', state: 'deployed', stack: 'production', vmid: 2, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    const result = getInstances();
    expect(result[0].name).toBe('alpha');
    expect(result[1].name).toBe('zebra');
  });

  it('filters by state', () => {
    createInstance({ name: 'a', state: 'deployed',  stack: 'production',  vmid: 1, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    createInstance({ name: 'b', state: 'degraded',  stack: 'production',  vmid: 2, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    createInstance({ name: 'c', state: 'testing',   stack: 'development', vmid: 3, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    expect(getInstances({ state: 'deployed' })).toHaveLength(1);
    expect(getInstances({ state: 'degraded' })).toHaveLength(1);
    expect(getInstances({ state: 'testing'  })).toHaveLength(1);
  });

  it('filters by stack', () => {
    createInstance({ name: 'a', state: 'deployed', stack: 'production',  vmid: 1, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    createInstance({ name: 'b', state: 'testing',  stack: 'development', vmid: 2, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    expect(getInstances({ stack: 'production'  })).toHaveLength(1);
    expect(getInstances({ stack: 'development' })).toHaveLength(1);
  });

  it('searches by name', () => {
    createInstance({ name: 'plex',  state: 'deployed', stack: 'production', vmid: 1, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    createInstance({ name: 'gitea', state: 'deployed', stack: 'production', vmid: 2, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    expect(getInstances({ search: 'ple' })).toHaveLength(1);
    expect(getInstances({ search: 'ple' })[0].name).toBe('plex');
  });

  it('searches by vmid', () => {
    createInstance({ name: 'a', state: 'deployed', stack: 'production', vmid: 137, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    createInstance({ name: 'b', state: 'deployed', stack: 'production', vmid: 200, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    expect(getInstances({ search: '137' })).toHaveLength(1);
  });

  it('combines filters', () => {
    createInstance({ name: 'plex',  state: 'deployed', stack: 'production', vmid: 1, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    createInstance({ name: 'plex2', state: 'degraded', stack: 'production', vmid: 2, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    expect(getInstances({ search: 'plex', state: 'deployed' })).toHaveLength(1);
  });
});

// ── getInstance ───────────────────────────────────────────────────────────────

describe('getInstance', () => {
  it('returns the instance with the given vmid', () => {
    createInstance({ name: 'plex', state: 'deployed', stack: 'production', vmid: 117, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    const inst = getInstance(117);
    expect(inst).not.toBeNull();
    expect(inst.name).toBe('plex');
    expect(inst.vmid).toBe(117);
  });

  it('returns null for unknown vmid', () => {
    expect(getInstance(999)).toBeNull();
  });
});

// ── getDistinctStacks ─────────────────────────────────────────────────────────

describe('getDistinctStacks', () => {
  it('returns empty array when table is empty', () => {
    expect(getDistinctStacks()).toEqual([]);
  });

  it('returns unique stacks sorted alphabetically', () => {
    createInstance({ name: 'a', state: 'deployed', stack: 'production',  vmid: 1, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    createInstance({ name: 'b', state: 'testing',  stack: 'development', vmid: 2, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    createInstance({ name: 'c', state: 'deployed', stack: 'production',  vmid: 3, atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 });
    expect(getDistinctStacks()).toEqual(['development', 'production']);
  });
});

// ── createInstance ────────────────────────────────────────────────────────────

describe('createInstance', () => {
  const base = { state: 'deployed', stack: 'production', atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 };

  it('inserts a new instance and sets timestamps', () => {
    createInstance({ ...base, name: 'traefik', vmid: 100 });
    const inst = getInstance(100);
    expect(inst.name).toBe('traefik');
    expect(inst.created_at).not.toBeNull();
    expect(inst.updated_at).not.toBeNull();
  });

  it('stores service flags correctly', () => {
    createInstance({ ...base, name: 'plex', vmid: 1, atlas: 1, tailscale: 1, hardware_acceleration: 1 });
    const inst = getInstance(1);
    expect(inst.atlas).toBe(1);
    expect(inst.argus).toBe(0);
    expect(inst.tailscale).toBe(1);
    expect(inst.hardware_acceleration).toBe(1);
  });

  it('rejects duplicate vmid', () => {
    createInstance({ ...base, name: 'a', vmid: 100 });
    expect(() => createInstance({ ...base, name: 'b', vmid: 100 })).toThrow();
  });

  it('rejects invalid state', () => {
    expect(() => createInstance({ ...base, name: 'a', vmid: 1, state: 'invalid' })).toThrow();
  });

  it('rejects invalid stack', () => {
    expect(() => createInstance({ ...base, name: 'a', vmid: 1, stack: 'invalid' })).toThrow();
  });
});

// ── updateInstance ────────────────────────────────────────────────────────────

describe('updateInstance', () => {
  const base = { state: 'deployed', stack: 'production', atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 };

  it('updates fields and refreshes updated_at', () => {
    createInstance({ ...base, name: 'old', vmid: 100 });
    updateInstance(100, { ...base, name: 'new', vmid: 100, state: 'degraded' });
    const inst = getInstance(100);
    expect(inst.name).toBe('new');
    expect(inst.state).toBe('degraded');
  });

  it('can change vmid', () => {
    createInstance({ ...base, name: 'a', vmid: 100 });
    updateInstance(100, { ...base, name: 'a', vmid: 200 });
    expect(getInstance(100)).toBeNull();
    expect(getInstance(200)).not.toBeNull();
  });
});

// ── deleteInstance ────────────────────────────────────────────────────────────

describe('deleteInstance', () => {
  const base = { state: 'deployed', stack: 'production', atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 };

  it('removes the instance', () => {
    createInstance({ ...base, name: 'a', vmid: 1 });
    deleteInstance(1);
    expect(getInstance(1)).toBeNull();
  });

  it('only removes the targeted instance', () => {
    createInstance({ ...base, name: 'a', vmid: 1 });
    createInstance({ ...base, name: 'b', vmid: 2 });
    deleteInstance(1);
    expect(getInstance(1)).toBeNull();
    expect(getInstance(2)).not.toBeNull();
  });
});

// ── importInstances ───────────────────────────────────────────────────────────

describe('importInstances', () => {
  const base = { state: 'deployed', stack: 'production', atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 };

  it('replaces all existing instances with the imported set', () => {
    createInstance({ ...base, name: 'old', vmid: 1 });
    importInstances([{ ...base, name: 'new', vmid: 2 }]);
    expect(getInstance(1)).toBeNull();
    expect(getInstance(2)).not.toBeNull();
  });

  it('clears all instances when passed an empty array', () => {
    createInstance({ ...base, name: 'a', vmid: 1 });
    importInstances([]);
    expect(getInstances()).toEqual([]);
  });
});

// ── instance history ─────────────────────────────────────────────────────────

describe('instance history', () => {
  const base = { state: 'deployed', stack: 'production', atlas: 0, argus: 0, semaphore: 0, patchmon: 0, tailscale: 0, andromeda: 0, tailscale_ip: '', hardware_acceleration: 0 };

  it('logs a created event when an instance is created', () => {
    createInstance({ ...base, name: 'a', vmid: 1 });
    const h = getInstanceHistory(1);
    expect(h).toHaveLength(1);
    expect(h[0].field).toBe('created');
  });

  it('logs changed fields when an instance is updated', () => {
    createInstance({ ...base, name: 'a', vmid: 1 });
    updateInstance(1, { ...base, name: 'a', vmid: 1, state: 'degraded' });
    const h = getInstanceHistory(1);
    const stateEvt = h.find(e => e.field === 'state');
    expect(stateEvt).toBeDefined();
    expect(stateEvt.old_value).toBe('deployed');
    expect(stateEvt.new_value).toBe('degraded');
  });

  it('logs no events when nothing changes on update', () => {
    createInstance({ ...base, name: 'a', vmid: 1 });
    updateInstance(1, { ...base, name: 'a', vmid: 1 });
    const h = getInstanceHistory(1).filter(e => e.field !== 'created');
    expect(h).toHaveLength(0);
  });

  it('records history under the new vmid when vmid changes', () => {
    createInstance({ ...base, name: 'a', vmid: 1 });
    updateInstance(1, { ...base, name: 'a', vmid: 2 });
    expect(getInstanceHistory(2).some(e => e.field === 'vmid')).toBe(true);
    expect(getInstanceHistory(1).filter(e => e.field !== 'created')).toHaveLength(0);
  });
});

// ── Test environment boot isolation ───────────────────────────────────────────

describe('test environment boot isolation', () => {
  it('vitest runs with NODE_ENV=test', () => {
    // Vitest sets NODE_ENV=test automatically. This is the guard condition
    // that prevents the boot init() from opening the real database file.
    expect(process.env.NODE_ENV).toBe('test');
  });

  it('db module loads cleanly in parallel workers without locking the real db file', () => {
    // Regression: the module-level init(DEFAULT_PATH) used to run unconditionally,
    // causing "database is locked" when multiple test workers imported db.js at
    // the same time. process.exit(1) then killed the worker mid-suite.
    // Fix: boot init is skipped when NODE_ENV=test. _resetForTest() handles setup.
    // Reaching this line proves the module loaded without calling process.exit.
    expect(() => _resetForTest()).not.toThrow();
    expect(getInstances()).toEqual([]);
  });
});