import { describe, expect, it } from 'vitest'
import type { AgentConfig } from '../src/config/agentConfig.js'
import {
  BindHostError,
  RootRefusedError,
  assertNativeZone,
  buildInstallOptions,
  detectPlatform,
  installService,
  normalizeBindHost,
  uninstallService,
  type InstallDeps,
} from '../src/service/install.js'
import { agentLabel, baseAppLabel, buildLaunchdPlist } from '../src/service/launchd.js'
import { agentUnitName, baseAppUnitName, buildSystemdUnit } from '../src/service/systemd.js'

const CFG: AgentConfig = {
  relayUrl: 'wss://relay/agent',
  enrollUrl: 'https://x/enroll',
  stateDir: '/tmp/x',
  localTargetUrl: 'ws://127.0.0.1:3000',
  subdomain: 'host-42',
  hostId: 'h-1',
}

type FakeDeps = InstallDeps & {
  writes: Array<[string, string]>
  runs: Array<[string, readonly string[]]>
}

function deps(uid = 501): FakeDeps {
  const writes: Array<[string, string]> = []
  const runs: Array<[string, readonly string[]]> = []
  return {
    writes,
    runs,
    writeFile: (p, c) => writes.push([p, c]),
    runCommand: async (cmd, args) => {
      runs.push([cmd, args])
    },
    getuid: () => uid,
    homedir: () => '/home/alice',
    username: () => 'alice',
    binPath: () => '/usr/local/bin/web-terminal-agent',
  }
}

/** The unit content whose path contains `needle` (e.g. `'base-app'`, `'agent'`). */
function unitWith(d: FakeDeps, needle: string): string {
  const hit = d.writes.find(([path]) => path.includes(needle))
  if (!hit) throw new Error(`no unit written whose path contains '${needle}'`)
  return hit[1]
}

describe('detectPlatform (T17)', () => {
  it('maps darwin→launchd, linux→systemd, else null', () => {
    expect(detectPlatform('darwin')).toBe('launchd')
    expect(detectPlatform('linux')).toBe('systemd')
    expect(detectPlatform('win32')).toBeNull()
  })
})

describe('installService — least privilege (T17)', () => {
  it('refuses to install as root (negative, least privilege)', async () => {
    await expect(installService(CFG, 'systemd', deps(0))).rejects.toBeInstanceOf(RootRefusedError)
  })

  it('root refusal emits nothing', async () => {
    const d = deps(0)
    await expect(installService(CFG, 'systemd', d)).rejects.toBeInstanceOf(RootRefusedError)
    expect(d.writes).toHaveLength(0)
    expect(d.runs).toHaveLength(0)
  })
})

describe('installService — two distinct units (FIX M-host-2service)', () => {
  it('systemd: writes a base-app unit AND an agent unit, both run-as-user, both enabled', async () => {
    const d = deps()
    await installService(CFG, 'systemd', d)
    // exactly two units
    expect(d.writes).toHaveLength(2)
    const baseApp = unitWith(d, baseAppUnitName())
    const agent = unitWith(d, agentUnitName())
    // agent unit supervises frpc via `<node> <bin> run` (absolute node so a minimal service PATH
    // that lacks /usr/local/bin can't fail with EX_CONFIG); base-app runs the node server (loopback)
    expect(agent).toContain('/usr/local/bin/web-terminal-agent run')
    expect(agent).toMatch(/ExecStart=\S*node\S* \/usr\/local\/bin\/web-terminal-agent run/)
    expect(baseApp).toContain('ExecStart=')
    expect(baseApp).toContain('server.js')
    expect(baseApp).not.toContain('web-terminal-agent run')
    // both least-privilege + restart-on-failure
    for (const unit of [baseApp, agent]) {
      expect(unit).toContain('User=alice')
      expect(unit).not.toContain('User=root')
      expect(unit).toContain('Restart=on-failure')
    }
    // both enabled
    expect(d.runs.every(([cmd]) => cmd === 'systemctl')).toBe(true)
    expect(d.runs).toHaveLength(2)
  })

  it('launchd: writes a base-app plist AND an agent plist, both with KeepAlive, both loaded', async () => {
    const d = deps()
    await installService(CFG, 'launchd', d)
    expect(d.writes).toHaveLength(2)
    const baseApp = unitWith(d, baseAppLabel())
    const agent = unitWith(d, agentLabel())
    expect(agent).toContain('<string>run</string>')
    expect(baseApp).toContain('server.js')
    expect(baseApp).not.toContain('<string>run</string>')
    for (const plist of [baseApp, agent]) {
      expect(plist).toContain('<key>KeepAlive</key>')
    }
    expect(d.writes.every(([path]) => path.includes('LaunchAgents'))).toBe(true)
    expect(d.runs.every(([cmd]) => cmd === 'launchctl')).toBe(true)
    expect(d.runs).toHaveLength(2)
  })

  it('routes base-app env to the base-app unit ONLY (never onto the agent unit)', async () => {
    const d = deps()
    await installService(CFG, 'systemd', d, { env: { BIND_HOST: '127.0.0.1', PORT: '3000' } })
    const baseApp = unitWith(d, baseAppUnitName())
    const agent = unitWith(d, agentUnitName())
    expect(baseApp).toContain('Environment="BIND_HOST=127.0.0.1"')
    expect(baseApp).toContain('Environment="PORT=3000"')
    // the agent unit must NOT carry the base-app env
    expect(agent).not.toContain('BIND_HOST')
    expect(agent).not.toContain('PORT=3000')
  })

  it('uninstall tears down BOTH units (launchd unload)', async () => {
    const d = deps()
    await uninstallService('launchd', d)
    const targets = d.runs.map(([, args]) => args[args.length - 1])
    expect(d.runs.every(([cmd]) => cmd === 'launchctl')).toBe(true)
    expect(targets.some((t) => t?.includes(baseAppLabel()))).toBe(true)
    expect(targets.some((t) => t?.includes(agentLabel()))).toBe(true)
  })

  it('uninstall tears down BOTH units (systemd disable)', async () => {
    const d = deps()
    await uninstallService('systemd', d)
    const units = d.runs.map(([, args]) => args[args.length - 1])
    expect(d.runs.every(([cmd]) => cmd === 'systemctl')).toBe(true)
    expect(units).toContain(baseAppUnitName())
    expect(units).toContain(agentUnitName())
  })
})

describe('BIND_HOST loopback S-GATE (FIX C-host-1, CRITICAL)', () => {
  it('normalizeBindHost defaults an absent value to loopback', () => {
    expect(normalizeBindHost(undefined)).toBe('127.0.0.1')
    expect(normalizeBindHost('')).toBe('127.0.0.1')
  })

  it('normalizeBindHost accepts loopback forms (127.0.0.0/8, ::1, localhost)', () => {
    expect(normalizeBindHost('127.0.0.1')).toBe('127.0.0.1')
    expect(normalizeBindHost('127.0.0.2')).toBe('127.0.0.2')
    expect(normalizeBindHost('::1')).toBe('::1')
    expect(normalizeBindHost('localhost')).toBe('localhost')
  })

  it('normalizeBindHost REJECTS 0.0.0.0 and other non-loopback values', () => {
    expect(() => normalizeBindHost('0.0.0.0')).toThrow(BindHostError)
    expect(() => normalizeBindHost('192.168.1.10')).toThrow(BindHostError)
    expect(() => normalizeBindHost('::')).toThrow(BindHostError)
  })

  it('REGRESSION: rejects a suffixed hostname that merely starts with 127. (S-GATE bypass)', () => {
    // These are hostnames, not loopback literals — Node would DNS-resolve them before bind().
    expect(() => normalizeBindHost('127.0.0.1.attacker.example.com')).toThrow(BindHostError)
    expect(() => normalizeBindHost('127.evil.net')).toThrow(BindHostError)
    expect(() => normalizeBindHost('127.0.0.1x')).toThrow(BindHostError)
    expect(() => buildInstallOptions({ BIND_HOST: '127.0.0.1.attacker.example.com' })).toThrow(
      BindHostError,
    )
  })

  it('buildInstallOptions throws on BIND_HOST=0.0.0.0 (fail-closed at env read)', () => {
    expect(() => buildInstallOptions({ BIND_HOST: '0.0.0.0' })).toThrow(BindHostError)
  })

  it('NEGATIVE: installService with BIND_HOST=0.0.0.0 throws AND emits nothing', async () => {
    const d = deps()
    await expect(
      installService(CFG, 'systemd', d, { env: { BIND_HOST: '0.0.0.0', PORT: '3000' } }),
    ).rejects.toBeInstanceOf(BindHostError)
    expect(d.writes).toHaveLength(0)
    expect(d.runs).toHaveLength(0)
  })

  it('NEGATIVE (launchd): a 0.0.0.0 install emits no plist', async () => {
    const d = deps()
    await expect(
      installService(CFG, 'launchd', d, { env: { BIND_HOST: '0.0.0.0' } }),
    ).rejects.toBeInstanceOf(BindHostError)
    expect(d.writes).toHaveLength(0)
  })

  it('the emitted base-app unit can NEVER contain BIND_HOST=0.0.0.0 (normalized when absent)', async () => {
    const d = deps()
    await installService(CFG, 'systemd', d, { env: { PORT: '3000' } })
    const baseApp = unitWith(d, baseAppUnitName())
    expect(baseApp).toContain('Environment="BIND_HOST=127.0.0.1"')
    expect(baseApp).not.toContain('0.0.0.0')
  })
})

describe('buildInstallOptions — env → InstallOptions (S0/S2 + S-GATE)', () => {
  it('defaults BIND_HOST to loopback so a tunnel install is never LAN-exposed (S0/R2)', () => {
    const options = buildInstallOptions({})
    expect(options.env).toEqual({ BIND_HOST: '127.0.0.1' })
  })

  it('honours an explicit loopback BIND_HOST and passes through the S0 base-app env vars', () => {
    const options = buildInstallOptions({
      BIND_HOST: '127.0.0.2',
      PORT: '3000',
      SHELL_PATH: '/bin/zsh',
      IDLE_TTL: '86400',
      USE_TMUX: '1',
      ALLOWED_ORIGINS: 'https://keep.me',
      SCROLLBACK_BYTES: '2097152',
      MAX_PAYLOAD_BYTES: '1048576',
    })
    expect(options.env).toEqual({
      BIND_HOST: '127.0.0.2',
      PORT: '3000',
      SHELL_PATH: '/bin/zsh',
      IDLE_TTL: '86400',
      USE_TMUX: '1',
      ALLOWED_ORIGINS: 'https://keep.me',
      SCROLLBACK_BYTES: '2097152',
      MAX_PAYLOAD_BYTES: '1048576',
    })
  })

  it('AG3: passes SCROLLBACK_BYTES and MAX_PAYLOAD_BYTES through as base-app config', () => {
    const options = buildInstallOptions({ SCROLLBACK_BYTES: '2097152', MAX_PAYLOAD_BYTES: '1048576' })
    expect(options.env).toEqual({
      BIND_HOST: '127.0.0.1',
      SCROLLBACK_BYTES: '2097152',
      MAX_PAYLOAD_BYTES: '1048576',
    })
  })

  it('omits unset/empty passthrough vars', () => {
    const options = buildInstallOptions({ PORT: '', SHELL_PATH: '/bin/bash' })
    expect(options.env).toEqual({ BIND_HOST: '127.0.0.1', SHELL_PATH: '/bin/bash' })
  })

  it('derives domain + default `terminal` zone from TUNNEL_DOMAIN', () => {
    const options = buildInstallOptions({ TUNNEL_DOMAIN: 'yaojia.wang' })
    expect(options.domain).toBe('yaojia.wang')
    expect(options.zone).toBe('terminal')
  })

  it('lets TUNNEL_ZONE override the origin zone and carries AGENT_ENV_FILE through', () => {
    const options = buildInstallOptions({
      TUNNEL_DOMAIN: 'yaojia.wang',
      TUNNEL_ZONE: 'term',
      AGENT_ENV_FILE: '/etc/wt.env',
    })
    expect(options.zone).toBe('term')
    expect(options.envFile).toBe('/etc/wt.env')
  })

  it('omits domain/zone when no TUNNEL_DOMAIN is set', () => {
    const options = buildInstallOptions({})
    expect(options.domain).toBeUndefined()
    expect(options.zone).toBeUndefined()
  })
})

describe('tunnel-origin derivation into the base-app unit (FIX L-host-zone)', () => {
  it('assertNativeZone accepts `terminal` and rejects `term`/undefined', () => {
    expect(() => assertNativeZone('terminal')).not.toThrow()
    expect(() => assertNativeZone('term')).toThrow(/terminal/)
    expect(() => assertNativeZone(undefined)).toThrow(/terminal/)
  })

  it('merges https://<sub>.terminal.<domain> into the base-app ALLOWED_ORIGINS', async () => {
    const d = deps()
    await installService(CFG, 'launchd', d, { domain: 'yaojia.wang', zone: 'terminal' })
    const baseApp = unitWith(d, baseAppLabel())
    expect(baseApp).toContain('<key>ALLOWED_ORIGINS</key>')
    expect(baseApp).toContain('<string>https://host-42.terminal.yaojia.wang</string>')
  })

  it('preserves a caller-provided ALLOWED_ORIGINS and appends the tunnel origin', async () => {
    const d = deps()
    await installService(CFG, 'systemd', d, {
      env: { ALLOWED_ORIGINS: 'https://keep.me' },
      domain: 'yaojia.wang',
      zone: 'terminal',
    })
    const baseApp = unitWith(d, baseAppUnitName())
    expect(baseApp).toContain('https://keep.me,https://host-42.terminal.yaojia.wang')
  })

  it('does not derive an origin when the config has no subdomain', async () => {
    const d = deps()
    await installService({ ...CFG, subdomain: null }, 'launchd', d, {
      domain: 'yaojia.wang',
      zone: 'terminal',
    })
    const baseApp = unitWith(d, baseAppLabel())
    expect(baseApp).not.toContain('ALLOWED_ORIGINS')
  })
})

describe('install CLI seam end-to-end — resolved env reaches the base-app unit (S2)', () => {
  const ENV = { PORT: '3000', SHELL_PATH: '/bin/zsh', TUNNEL_DOMAIN: 'yaojia.wang' } as const

  it('launchd: the base-app plist carries loopback BIND_HOST + the derived tunnel ALLOWED_ORIGINS', async () => {
    const d = deps()
    await installService(CFG, 'launchd', d, buildInstallOptions(ENV))
    const baseApp = unitWith(d, baseAppLabel())
    expect(baseApp).toContain('<key>BIND_HOST</key>')
    expect(baseApp).toContain('<string>127.0.0.1</string>')
    expect(baseApp).toContain('<string>https://host-42.terminal.yaojia.wang</string>')
    expect(baseApp).toContain('<key>PORT</key>')
    expect(baseApp).not.toContain('0.0.0.0')
  })

  it('systemd: the base-app unit carries loopback BIND_HOST + the derived tunnel ALLOWED_ORIGINS', async () => {
    const d = deps()
    await installService(CFG, 'systemd', d, buildInstallOptions(ENV))
    const baseApp = unitWith(d, baseAppUnitName())
    expect(baseApp).toContain('Environment="BIND_HOST=127.0.0.1"')
    expect(baseApp).toContain('Environment="ALLOWED_ORIGINS=https://host-42.terminal.yaojia.wang"')
    expect(baseApp).toContain('Environment="PORT=3000"')
    expect(baseApp).not.toContain('0.0.0.0')
  })

  it('systemd: emits EnvironmentFile= (before inline Environment) on the base-app unit', async () => {
    const d = deps()
    await installService(CFG, 'systemd', d, {
      env: { BIND_HOST: '127.0.0.1', PORT: '3000' },
      envFile: '/etc/web-terminal.env',
    })
    const baseApp = unitWith(d, baseAppUnitName())
    expect(baseApp).toContain('EnvironmentFile=/etc/web-terminal.env')
    expect(baseApp.indexOf('EnvironmentFile=')).toBeLessThan(baseApp.indexOf('Environment='))
  })
})

describe('unit writers — escaping & control-char hardening', () => {
  it('launchd: escapes XML-significant characters in env values', () => {
    const plist = buildLaunchdPlist(['/bin/agent', 'run'], { X: `a&b<c>d"e'f` })
    expect(plist).toContain('<string>a&amp;b&lt;c&gt;d&quot;e&apos;f</string>')
    expect(plist).not.toContain('a&b<c>d')
  })

  it('launchd: injects a sorted, XML-escaped EnvironmentVariables dict', () => {
    const plist = buildLaunchdPlist(['/bin/agent', 'run'], {
      BIND_HOST: '127.0.0.1',
      ALLOWED_ORIGINS: 'https://a',
      PORT: '3000',
    })
    expect(plist).toContain('<key>EnvironmentVariables</key>')
    expect(plist.indexOf('ALLOWED_ORIGINS')).toBeLessThan(plist.indexOf('BIND_HOST'))
    expect(plist.indexOf('BIND_HOST')).toBeLessThan(plist.indexOf('>PORT<'))
  })

  it('launchd: no env → no EnvironmentVariables block', () => {
    const plist = buildLaunchdPlist(['/bin/agent', 'run'])
    expect(plist).not.toContain('EnvironmentVariables')
  })

  it('systemd: escapes backslash and double-quote in Environment values', () => {
    const unit = buildSystemdUnit('/bin/agent run', 'alice', { env: { X: 'a"b\\c' } })
    expect(unit).toContain('Environment="X=a\\"b\\\\c"')
  })

  it('systemd: rejects a newline in an env value (no [Service] directive injection)', () => {
    expect(() =>
      buildSystemdUnit('/bin/agent run', 'alice', { env: { X: 'a\nExecStartPre=/x' } }),
    ).toThrow(/control character/)
  })

  it('systemd: rejects a carriage return in an env value', () => {
    expect(() => buildSystemdUnit('/bin/agent run', 'alice', { env: { X: 'a\rb' } })).toThrow(
      /control character/,
    )
  })

  it('AG2: rejects a newline in the ExecStart command (no [Service] directive injection)', () => {
    expect(() =>
      buildSystemdUnit('/bin/agent run\nExecStartPre=/x', 'alice'),
    ).toThrow(/control character/)
  })

  it('AG2: rejects a newline in the User field', () => {
    expect(() => buildSystemdUnit('/bin/agent run', 'alice\nExecStartPre=/x')).toThrow(
      /control character/,
    )
  })

  it('AG2: rejects a newline in the Description field', () => {
    expect(() =>
      buildSystemdUnit('/bin/agent run', 'alice', {}, 'desc\n[Service]\nExecStartPre=/x'),
    ).toThrow(/control character/)
  })

  it('AG2: rejects a newline in the EnvironmentFile path', () => {
    expect(() =>
      buildSystemdUnit('/bin/agent run', 'alice', { envFile: '/etc/x.env\nExecStartPre=/y' }),
    ).toThrow(/control character/)
  })

  it('AG2: rejects a newline in an Environment KEY (not just the value)', () => {
    expect(() =>
      buildSystemdUnit('/bin/agent run', 'alice', { env: { 'X\nExecStartPre=/y': 'v' } }),
    ).toThrow(/control character/)
  })

  it('systemd: default (no env) omits Environment lines', () => {
    const unit = buildSystemdUnit('/bin/agent run', 'alice')
    expect(unit).not.toContain('Environment')
  })
})