/**
 * The browser half: the two keys it binds, and the fields it stages.
 *
 * This file exists because of a bug that no host-side test could catch. Marking
 * the schema's fields `volatile()` makes the Host *serve* the namespace, but the
 * Plugins page draws only what a browser half registers — so the plugin showed no
 * settings card at all, and every host-side test passed.
 *
 * The wiring is therefore the thing worth testing, and the two keys are the trap:
 * the settings DOCUMENT is keyed by the profile entry id (`facet-policy`) while
 * the CARD is keyed by the package name (`dsh-facet`). Every sibling plugin
 * happens to name those identically, which is exactly why this drifted. A card
 * bound to the wrong id renders, saves, and writes nowhere.
 *
 * `client/client.js` is a `window.__ModuleLoader__` module rather than an ES
 * module — that is how the harness loads a browser half without a bundler — so
 * the test stands up the two globals it reads and drives it from there.
 */

import assert from 'node:assert/strict'
import { readFile } from 'node:fs/promises'
import { test } from 'node:test'

import { Config } from '../index.js'

/** Load the browser half with `window` and `require` faked, as the seed would. */
async function loadClient() {
  const source = await readFile(new URL('../client/client.js', import.meta.url), 'utf8')

  /** Every spec a card staged, in construction order. */
  const staged = []

  const primitives = {
    Modal: 'Modal',
    SettingsForm: 'SettingsForm',
    SettingsValueField: 'SettingsValueField',
    SegmentedControl: 'SegmentedControl',
    /** Stands in for the real model: records the specs and answers with the value. */
    SettingsFormModel: class {
      constructor(scope, specs) {
        this.scope = scope
        this.specs = specs
        staged.push(...specs)
      }
      bind(project) {
        this.project = project
        return { project }
      }
      shell() {
        return { available: true, writable: true, dirty: false, invalid: false, saving: false, failed: false }
      }
      field(name) {
        const spec = this.specs.find((candidate) => candidate.field === name)
        return { text: spec?.format(this.scope.value?.[name]) ?? '', overridden: false, invalid: false }
      }
      actions() {
        return { edit: () => {}, resetField: () => {}, save: () => {}, discard: () => {} }
      }
      dispose() {}
    },
  }

  const require = (id) => {
    if (id === 'react') {
      return {
        createElement: (type, props, ...children) => ({ type, props, children }),
        // Single-pass stand-ins: the tests render a component once and read the
        // tree, so a hook only has to answer, not to re-render.
        useState: (initial) => [typeof initial === 'function' ? initial() : initial, () => {}],
        useSyncExternalStore: (_subscribe, getSnapshot) => getSnapshot(),
      }
    }
    if (id === '@deepseek-ai/dsh-client-ui-primitives') return primitives
    throw new Error(`client.js required an unexpected module: ${id}`)
  }

  let registered
  const loader = { load: (value) => (registered = value) }
  // eslint-disable-next-line no-new-func -- the file is a ModuleLoader script, not an ES module.
  new Function('window', 'require', source)({ __ModuleLoader__: loader }, require)

  assert.notEqual(registered, undefined, 'client.js never called window.__ModuleLoader__.load')
  return { module: registered.factory(require), staged, primitives }
}

/** Drive `apply` against a fake slot/configForms surface and report what it did. */
function drive(mod, { served = true, value = {} } = {}) {
  const seen = { formNs: undefined, watched: undefined, registrations: [] }
  const disposers = []
  let currentSlot

  const ctx = {
    inject: (names, scope) => {
      const scoped = {
        configForms: {
          get: (ns) => {
            seen.formNs = ns
            return { value, getSnapshot: () => ({ value, writable: true }), subscribe: () => () => {}, mutate: () => true }
          },
          whileServed: (namespaces, register) => {
            seen.watched = namespaces
            // The real `whileServed` registers only while the Host serves the
            // namespace; `served` is what the Host's `settings.describe` answers.
            if (!served) return () => {}
            return register(new Set(namespaces))
          },
        },
        slots: {
          inject: (name, register) => {
            currentSlot = name
            register()
            currentSlot = undefined
          },
          register: (options, component) => {
            seen.registrations.push({ slot: currentSlot, options, component })
            return () => {}
          },
        },
        effect: (fn) => {
          const dispose = fn()
          if (typeof dispose === 'function') disposers.push(dispose)
          return dispose
        },
      }
      scope(scoped)
    },
  }

  mod.apply(ctx)
  return { seen, disposers }
}

/** The one registration a test cares about, by the slot it went into. */
function registrationFor(seen, slot) {
  const found = seen.registrations.filter((entry) => entry.slot === slot)
  assert.equal(found.length, 1, `expected exactly one registration into ${slot}`)
  return found[0]
}

test('the module is the one the Plugins page loads, and asks for the slots it registers into', async () => {
  const { module: mod } = await loadClient()
  assert.equal(mod.name, 'dsh-facet')
  assert.deepEqual(mod.inject, ['slots'])
  assert.equal(typeof mod.apply, 'function')
})

test('the form binds to the profile entry id while the card registers under the package name', async () => {
  const { module: mod } = await loadClient()
  const { seen } = drive(mod)
  const card = registrationFor(seen, 'plugins.bundle.config')

  // These two are deliberately different strings. `facet-policy` is the `id` of
  // this bundle's row in cordis.patch.yml — what `Config` is filed under. The
  // card is dispatched by the BUNDLE's package name.
  assert.equal(seen.formNs, 'facet-policy')
  assert.equal(card.options.key, 'dsh-facet')
  assert.notEqual(seen.formNs, card.options.key, 'if these ever coincide, the trap this test guards has moved')

  assert.equal(card.slot, 'plugins.bundle.config')
  assert.deepEqual(seen.watched, ['facet-policy'])
})

test('the context button rides the composer tool row, gated on the same namespace', async () => {
  const { module: mod } = await loadClient()
  const { seen } = drive(mod)
  const button = registrationFor(seen, 'conversation.input.left')

  // An id, not a key: `conversation.input.left` is a list, and the row shows one
  // entry per id.
  assert.equal(button.options.id, 'facet-context')
  assert.equal(typeof button.options.inject, 'function')
  // It has to receive the settings form, because the panel writes through the
  // very same document the plugin card does.
  assert.equal(typeof button.options.inject().form, 'object')
})

test('the host row the form binds to is the one cordis.patch.yml actually declares', async () => {
  const patch = await readFile(new URL('../cordis.patch.yml', import.meta.url), 'utf8')
  const { module: mod } = await loadClient()
  const { seen } = drive(mod)
  const card = registrationFor(seen, 'plugins.bundle.config')

  // A rename in the patch without a rename here is a card that writes nowhere,
  // so the id is read out of the patch rather than trusted to the test.
  assert.match(patch, new RegExp(`id:\\s*${seen.formNs}\\b`))
  assert.equal((await import('../package.json', { with: { type: 'json' } })).default.name, card.options.key)
})

test('nothing is registered while the Host does not serve the namespace', async () => {
  const { module: mod } = await loadClient()
  const { seen } = drive(mod, { served: false })
  assert.equal(seen.formNs, 'facet-policy', 'the form is still bound')
  // Neither the card nor the button: each would be a control that writes nowhere.
  assert.deepEqual(seen.registrations, [])
})

test('the card stages exactly the deployment fields the host marks volatile', async () => {
  const { module: mod, staged } = await loadClient()
  drive(mod)

  const volatileFields = Object.entries(Config.dict)
    .filter(([, schema]) => schema.meta.volatile === true)
    .map(([key]) => key)

  // `scopes` is volatile too, but it is not a deployment field and must not be a
  // control on the card: it is per-session state, written by the context panel
  // and keyed by session id. Staging it here would render a dictionary blob a
  // user could not sensibly edit, and would put the panel's store on the one
  // surface that edits the deployment.
  assert.ok(volatileFields.includes('scopes'), 'scopes must be volatile or the panel cannot write it')
  const declared = volatileFields.filter((key) => key !== 'scopes')

  // A field served but never staged is invisible in the UI; a field staged but
  // never served makes `whileServed` withhold the whole card.
  assert.deepEqual(
    staged.map((spec) => spec.field).sort(),
    declared.sort(),
    'the card and the host schema have drifted apart',
  )
})

test('the choice field refuses a value the schema would reject, and clears on empty', async () => {
  const { module: mod, staged } = await loadClient()
  drive(mod)
  const mode = staged.find((spec) => spec.field === 'mode')

  assert.equal(mode.parse('deny').value, 'deny')
  assert.equal(mode.parse(' DENY ').value, 'deny')
  assert.deepEqual(mode.parse(''), { kind: 'clear' })
  // Undefined marks the draft invalid, which blocks the save rather than
  // coercing a typo into a mode the Host would reject anyway.
  assert.equal(mode.parse('maybe'), undefined)
})

test('the list field clears rather than storing an empty array that shadows the default', async () => {
  const { module: mod, staged } = await loadClient()
  drive(mod)
  const roots = staged.find((spec) => spec.field === 'extraRoots')

  assert.deepEqual(roots.parse('a, b\nc').value, ['a', 'b', 'c'])
  assert.deepEqual(roots.parse('   '), { kind: 'clear' })
  assert.equal(roots.format(['a', 'b']), 'a, b')
  assert.equal(roots.format(undefined), '')
})

test('the card renders both views without reaching for anything it was not given', async () => {
  const { module: mod } = await loadClient()
  const { seen } = drive(mod)
  const { component: card } = registrationFor(seen, 'plugins.bundle.config')

  assert.equal(typeof card, 'function')
  assert.equal(card({ view: 'summary' }), 'How a call outside the session\u2019s own folder is handled, and which paths are always in scope.')

  const tree = card({
    view: 'page',
    useFacetCard: (select) =>
      select({
        available: true,
        writable: true,
        dirty: false,
        invalid: false,
        saving: false,
        failed: false,
        mode: { text: 'deny', overridden: false, invalid: false },
        extraRoots: { text: 'src/shared', overridden: true, invalid: false },
      }),
    edit: () => {},
    resetField: () => {},
    save: () => {},
    discard: () => {},
  })

  // The form frame, with the segmented control reading the staged mode. Children
  // ride the `children` prop, which is how the platform's own cards pass them.
  assert.equal(tree.type, 'SettingsForm')
  const controls = tree.props.children.children
  assert.equal(controls[0].type, 'div')
  assert.equal(controls[1].type, 'SettingsValueField')
  assert.equal(controls[0].children[1].props.value, 'deny')
  assert.equal(controls[1].props.text, 'src/shared')
})

test('the client half loads the packages whose slots it registers into', async () => {
  const pkg = (await import('../package.json', { with: { type: 'json' } })).default
  const inject = pkg.dsh.client.inject

  // Registering into a slot is a dependency on the package that declares it.
  // `slots.inject` waits for a slot rather than creating one, so a half that
  // names a slot belonging to a package the boot graph has not loaded yet
  // registers nothing at all — and silently, because nothing errors.
  assert.ok(inject.includes('@deepseek-ai/dsh-client-ui-plugin-manager'), 'registers into plugins.bundle.config')
  assert.ok(inject.includes('@deepseek-ai/dsh-client-ui-conversation'), 'registers into conversation.input.left')
  assert.ok(inject.includes('@deepseek-ai/dsh-client-ui-settings'), 'reads configForms')
})

// ── the context button and panel ─────────────────────────────────────────────

test('the context button appears for a facet session and nowhere else', async () => {
  const { module: mod } = await loadClient()
  const { seen } = drive(mod)
  const { component: button, options } = registrationFor(seen, 'conversation.input.left')
  const { form } = options.inject()

  const render = (preset) =>
    button({
      sessionId: 'session-1',
      useSessions: (select) => select({ byId: { 'session-1': { projectionValues: { agentPreset: preset } } } }),
      locked: false,
      form,
    })

  assert.notEqual(render('facet'), null)
  // Every other preset in the deployment is untouched: a control for a plugin
  // that is not running would be worse than no control.
  assert.equal(render('standard'), null)
  assert.equal(render(undefined), null)
})

test('declaredFor normalises whatever the document holds', async () => {
  const { module: mod } = await loadClient()

  assert.deepEqual(mod.declaredFor({ value: { scopes: { a: { focus: 'src/x', extras: ['p'] } } } }, 'a'), {
    focus: 'src/x',
    extras: ['p'],
  })
  // A session with no entry, a document with no scopes, and junk in either all
  // answer with the same empty declaration rather than throwing in a render.
  const empty = { focus: '', extras: [] }
  assert.deepEqual(mod.declaredFor({ value: {} }, 'a'), empty)
  assert.deepEqual(mod.declaredFor({}, 'a'), empty)
  assert.deepEqual(mod.declaredFor({ value: { scopes: { a: 'nonsense' } } }, 'a'), empty)
  assert.deepEqual(mod.declaredFor({ value: { scopes: { a: { focus: 7, extras: ['ok', 3, null] } } } }, 'a'), {
    focus: '',
    extras: ['ok'],
  })
})

test('writeDeclaration writes one whole declaration, and removes an empty one', async () => {
  const { module: mod } = await loadClient()
  const calls = []
  const form = { mutate: (ops) => (calls.push(ops), true) }

  mod.writeDeclaration(form, 'session-1', { focus: ' src/x ', extras: ['p', ' ', 'q'] })
  mod.writeDeclaration(form, 'session-1', { focus: '', extras: [] })

  // One path, one write: a queued edit can never half-apply.
  assert.deepEqual(calls[0], [{ op: 'set', path: ['scopes', 'session-1'], value: { focus: 'src/x', extras: ['p', 'q'] } }])
  // Both fields empty means "the session directory", which is the schema default
  // — so it is removed rather than stored as an empty override.
  assert.deepEqual(calls[1], [{ op: 'unset', path: ['scopes', 'session-1'] }])
})

test('the panel renders the scope, the guidance, and a way to add and remove', async () => {
  const { module: mod } = await loadClient()
  const written = []
  const form = {
    getSnapshot: () => ({
      status: 'ready',
      writable: true,
      revision: 4,
      value: { mode: 'deny', scopes: { 'session-1': { focus: 'src/room', extras: ['CONTROLLER.md'] } } },
    }),
    subscribe: () => () => {},
    mutate: (ops) => (written.push(ops), true),
  }

  const tree = mod.FacetContextPanel({ form, sessionId: 'session-1', mode: 'deny', onClose: () => {} })
  assert.equal(tree.type, 'Modal')

  // Walk the tree for the text and controls a user would see.
  const texts = []
  const buttons = []
  const inputs = []
  const walk = (node) => {
    if (typeof node === 'string') return texts.push(node)
    if (node === null || node === undefined || typeof node !== 'object') return
    if (Array.isArray(node)) return node.forEach(walk)
    if (node.type === 'button') buttons.push(node)
    if (node.type === 'input') inputs.push(node)
    // Children arrive either as createElement arguments or, as the card does it,
    // through the `children` prop.
    if (Array.isArray(node.children)) node.children.forEach(walk)
    walk(node.props?.children)
  }
  walk(tree)

  const labelOf = (node) => (node.children ?? [])[0]

  const prose = texts.join('\n')
  assert.match(prose, /What this conversation may see/)
  // The two tabs the preset picker cannot show for a custom preset live here.
  assert.match(prose, /Mode details/)
  assert.match(prose, /How to use/)
  // The honest bit about this deployment, so the panel does not promise a
  // question no approval channel can carry.
  assert.match(prose, /no approval channel/)
  assert.match(prose, /danger-full-access/)

  // The declared scope is on screen, and the existing extra has its own control.
  assert.equal(inputs[0].props.value, 'src/room')
  assert.equal(buttons.filter((button) => labelOf(button) === 'Remove').length, 1)
  assert.ok(buttons.some((button) => labelOf(button) === 'Add'))
  assert.ok(buttons.some((button) => labelOf(button) === 'Clear'))
  assert.ok(buttons.some((button) => labelOf(button) === 'Set'))
})