// A new stack — written as compose, or filled in as a form that writes the compose for you.
// "New container" is the same dialog opened on the form: a container made here is a
// one-service stack, so it can be edited, redeployed and updated like everything else on the
// page, where a bare `docker run` could only ever be thrown away and typed again.
// "Duplicate" is the same dialog again, opened on an existing stack's compose text.
import { useEffect, useMemo, useState } from 'react'
import { api, StackHome } from './api'
import { askYes, Btn, Loading, useEscape } from './ui'

interface Form { image: string; ports: string; volumes: string; env: string; labels: string; restart: string; command: string; network: string }
const EMPTY: Form = { image: '', ports: '', volumes: '', env: '', labels: '', restart: 'unless-stopped', command: '', network: '' }
const START = 'services:\n  app:\n    image: nginx:alpine\n    restart: unless-stopped\n    ports:\n      - "8080:80"\n'
const lines = (t: string) => t.split('\n').map((x) => x.trim()).filter(Boolean)
const q = (v: string) => JSON.stringify(v) // a JSON string is a valid YAML string, with every awkward character already dealt with
const dollars = (v: string) => v.replace(/\$/g, '$$$$') // a literal $ would be read by compose as a variable: doubled, it is a dollar again

// network: '' is compose's default (a network of the stack's own), 'host' is the machine's, anything
// else is a network that already exists — joined, and declared external so compose doesn't make another.
export function composeOf(name: string, f: Form): string {
  const svc = name || 'app'
  const out = ['services:', `  ${svc}:`, `    image: ${q(f.image.trim() || 'nginx:alpine')}`, `    container_name: ${q(svc)}`]
  if (f.restart !== 'no') out.push(`    restart: ${f.restart}`)
  if (f.command.trim()) out.push(`    command: ${q(f.command.trim())}`)
  if (f.network === 'host') out.push('    network_mode: host')
  else if (lines(f.ports).length) out.push('    ports:', ...lines(f.ports).map((p) => `      - ${q(p)}`))
  if (f.network && f.network !== 'host') out.push('    networks:', `      - ${q(f.network)}`)
  if (lines(f.volumes).length) out.push('    volumes:', ...lines(f.volumes).map((v) => `      - ${q(v)}`))
  if (lines(f.env).length) out.push('    environment:', ...lines(f.env).map((e) => `      - ${q(dollars(e))}`))
  if (lines(f.labels).length) out.push('    labels:', ...lines(f.labels).map((l) => `      - ${q(dollars(l))}`))
  if (f.network && f.network !== 'host') out.push('networks:', `  ${q(f.network)}:`, '    external: true')
  return out.join('\n') + '\n'
}

// the last two folders say which home it is; the whole path is written out under the box
const tail = (dir: string) => '…/' + dir.split('/').filter(Boolean).slice(-2).join('/')

export interface DupFrom { name: string; text: string; hasEnv: boolean; files: number }
export interface Taken { names: string[]; ports: Record<string, string> } // container names in use · published host port → who has it

interface Props { mode: 'stack' | 'container'; from?: DupFrom; networks?: string[]; taken?: Taken; onClose: () => void; onCreated: (name: string, deploy: boolean) => void }

export default function StackNew({ mode, from, networks = [], taken, onClose, onCreated }: Props) {
  const startName = from ? `${from.name}-copy`.slice(0, 63) : ''
  const startText = from?.text ?? START
  const [homes, setHomes] = useState<StackHome[] | null>(null)
  const [home, setHome] = useState('')
  const [name, setName] = useState(startName)
  const [how, setHow] = useState<'form' | 'compose'>(mode === 'container' ? 'form' : 'compose')
  const [form, setForm] = useState<Form>(EMPTY)
  const [text, setText] = useState(startText)
  const [env, setEnv] = useState('')
  const [copyEnv, setCopyEnv] = useState(!!from?.hasEnv)
  const [err, setErr] = useState('')
  const [seeded, setSeeded] = useState('') // what the form last wrote into the compose box
  // a stray tap outside, or Escape, must not throw away a compose file someone has typed
  const typed = name !== startName || !!env || text !== startText || JSON.stringify(form) !== JSON.stringify(EMPTY)
  const close = async () => { if (!typed || (await askYes('Discard this new ' + mode + '? What you have typed is lost.', 'Discard'))) onClose() }
  useEscape(close)
  useEffect(() => { api.stackHomes().then((r) => { const hs = r.homes ?? []; setHomes(hs); setHome(hs.find((h) => h.default)?.dir ?? hs[0]?.dir ?? '') }).catch((e) => setErr(e instanceof Error ? e.message : 'failed')) }, [])
  const okName = /^[a-z0-9][a-z0-9_-]{0,62}$/.test(name)
  const built = useMemo(() => composeOf(name, form), [name, form])
  const compose = how === 'form' ? built : text
  const picked = homes?.find((h) => h.dir === home)
  // What would collide with something already running. A warning, not a refusal: the stack may be
  // meant to replace that container, and "Create only" collides with nothing.
  const clashes = useMemo(() => {
    if (!taken) return []
    const out: string[] = []
    for (const m of compose.matchAll(/^\s*container_name:\s*["']?([^"'\s#]+)/gm)) if (taken.names.includes(m[1])) out.push(`a container called ${m[1]} already exists`)
    if (!/^\s*network_mode:\s*["']?host/m.test(compose)) for (const m of compose.matchAll(/^\s*-\s*["']?(?:\d{1,3}(?:\.\d{1,3}){3}:)?(\d+):\d+/gm)) if (taken.ports[m[1]]) out.push(`port ${m[1]} is already published by ${taken.ports[m[1]]}`)
    return [...new Set(out)]
  }, [compose, taken])
  const create = (deploy: boolean) => async () => {
    try { await api.createStack({ name, text: compose, env: from && copyEnv ? '' : env, home, env_from: from && copyEnv ? from.name : undefined }); onCreated(name, deploy) } catch (e) { setErr(e instanceof Error ? e.message : 'failed') }
  }
  // The form writes the compose box only when the form has something new to say; text edited by
  // hand since is asked about, never silently replaced.
  const toCompose = async () => {
    if (how === 'form' && form.image.trim() && built !== seeded) {
      const mine = text !== startText && text !== seeded
      if (!mine || (await askYes('Replace the compose text you edited with what the form says now?', 'Replace'))) { setText(built); setSeeded(built) }
    }
    setHow('compose')
  }
  const set = (k: keyof Form) => (e: { target: { value: string } }) => setForm({ ...form, [k]: e.target.value })
  const sameTail = (h: StackHome) => (homes ?? []).filter((o) => tail(o.dir) === tail(h.dir)).length > 1
  return (
    <div className="modal-back" onClick={close}>
      <div className="modal stack-new" onClick={(e) => e.stopPropagation()}>
        <h3>{from ? `Duplicate ${from.name}` : mode === 'container' ? 'New container' : 'New stack'}</h3>
        {mode === 'container' && <div className="muted small">Made as a one-service stack, so you can edit it, redeploy it and update its image later from the Stacks tab.</div>}
        {from && <div className="muted small">A new stack that starts as a copy of {from.name}'s compose file{from.files > 1 ? ` (its first file only: ${from.name} is made of ${from.files})` : ''}. {from.name} itself is not changed. Volumes and bind-mounted folders named in it would be <b>shared</b> with the original unless you change them.</div>}
        {!homes && !err && <Loading label="Finding where this machine keeps its stacks…" />}
        {homes && homes.length === 0 && <div className="notice">Docker isn't installed on this machine.</div>}
        {homes && homes.length > 0 && <>
          <label className="muted">Name
            <input autoFocus className="mono" value={name} onChange={(e) => { setName(e.target.value.toLowerCase()); setErr('') }} placeholder={mode === 'container' ? 'whoami' : 'my-stack'} maxLength={63} spellCheck={false} autoCapitalize="off" autoCorrect="off" />
          </label>
          {name && !okName && <div className="error">lower-case letters, digits, - and _ — starting with a letter or digit</div>}
          {homes.length > 1 && <label className="muted">Where
            <select value={home} onChange={(e) => setHome(e.target.value)}>{homes.map((h) => <option key={h.dir + h.via} value={h.dir}>{sameTail(h) ? h.dir : tail(h.dir)} · {h.stacks} stack{h.stacks === 1 ? '' : 's'}</option>)}</select>
          </label>}
          {picked && <div className="muted small mono" style={{ overflowWrap: 'anywhere' }}>{picked.dir}/{name || '…'}/compose.yaml{picked.held_by && ` — kept on ${picked.held_by}, deployed here over ${picked.remote}`}{picked.via && ` — compose runs inside ${picked.via}, like its neighbours`}</div>}
          {!from && <div className="tabs"><button className={how === 'form' ? 'on' : ''} onClick={() => setHow('form')}>Form</button><button className={how === 'compose' ? 'on' : ''} onClick={toCompose}>Compose</button></div>}
          {how === 'form' ? <>
            <label className="muted">Image<input className="mono" value={form.image} onChange={set('image')} placeholder="traefik/whoami:latest" spellCheck={false} autoCapitalize="off" autoCorrect="off" /></label>
            <div className="two">
              <label className="muted">Ports — host:container, one per line<textarea className="mono" rows={2} value={form.ports} onChange={set('ports')} placeholder={'8080:80'} disabled={form.network === 'host'} spellCheck={false} /></label>
              <label className="muted">Volumes — host path or name : container path<textarea className="mono" rows={2} value={form.volumes} onChange={set('volumes')} placeholder={'/home/core/apps/whoami:/data'} spellCheck={false} /></label>
            </div>
            <div className="two">
              <label className="muted">Environment — KEY=value, one per line<textarea className="mono" rows={2} value={form.env} onChange={set('env')} placeholder={'TZ=America/Los_Angeles'} spellCheck={false} /></label>
              <label className="muted">Labels — key=value, one per line<textarea className="mono" rows={2} value={form.labels} onChange={set('labels')} placeholder={'com.example.owner=mitchell'} spellCheck={false} /></label>
            </div>
            <div className="two">
              <label className="muted">Restart<select value={form.restart} onChange={set('restart')}><option value="unless-stopped">unless-stopped</option><option value="always">always</option><option value="on-failure">on-failure</option><option value="no">no</option></select></label>
              <label className="muted">Network<select value={form.network} onChange={set('network')}><option value="">its own (the default)</option><option value="host">host — this machine's network; ports don't apply</option>{networks.map((n) => <option key={n} value={n}>join {n}</option>)}</select></label>
            </div>
            <label className="muted">Command (optional)<input className="mono" value={form.command} onChange={set('command')} spellCheck={false} autoCapitalize="off" /></label>
            <pre className="unit-file stack-preview">{built}</pre>
          </> : <>
            <textarea className="editor stack-editor" value={text} onChange={(e) => setText(e.target.value)} spellCheck={false} autoCapitalize="off" autoCorrect="off" />
            {from?.hasEnv && <label className="check"><input type="checkbox" checked={copyEnv} onChange={(e) => setCopyEnv(e.target.checked)} /> <span>Copy {from.name}'s .env too <span className="muted">— copied on the machine itself; its values are never shown here</span></span></label>}
            {!(from && copyEnv) && <label className="muted">.env (optional) — variables the compose file reads; kept readable by root only
              <textarea className="mono" rows={2} value={env} onChange={(e) => setEnv(e.target.value)} placeholder={'SECRET=…'} spellCheck={false} />
            </label>}
          </>}
          <div className="modal-foot">
            {clashes.length > 0 && <div className="clash">Deploying this as it stands would fail: {clashes.join('; ')}.</div>}
            {err && <div className="error" style={{ whiteSpace: 'pre-wrap' }}>{err}</div>}
            <div className="svc-actions">
              <Btn className="btn on" disabled={!okName || (how === 'form' && !form.image.trim())} onClick={create(true)}>Create and deploy</Btn>
              <Btn className="btn" disabled={!okName || (how === 'form' && !form.image.trim())} onClick={create(false)}>Create only</Btn>
              <span className="spacer" /><button className="btn" onClick={close}>Cancel</button>
            </div>
          </div>
        </>}
        {err && !homes && <div className="error">{err}</div>}
      </div>
    </div>
  )
}