/**
 * Behavioural contract for the loop that promotes snapshot sections.
 *
 * The loop only earns its keep if a promoted recall block reaches the SYSTEM
 * prompt and does NOT reach history. These tests pin exactly that, plus the
 * cases where it must keep its hands off.
 *
 *   P1  a pure snapshot carrier message moves into `assembly.sections`.
 *   P2  the returned decision is a NEW object; the input is not mutated.
 *   P3  the promoted section carries `interpolate: false` — free text with
 *       `{{...}}` must not reach the strict interpolator.
 *   P4a a carrier whose content text equals its sections IS promoted (the real
 *       path: `lib/index.js:932` always attaches one text block); P4b the same
 *       message with differing content is NOT; P4c proves the split is decided
 *       by text equality, not by the presence of content.
 *   P5  a non-snapshot message is NOT promoted.
 *   P6  a name collision suffixes instead of overwriting or dropping.
 *   P7  `reject` decisions pass through untouched.
 *   P8  a decision with no `assembly` passes through untouched.
 *   P9  everything that is not promoted survives in `messages`, in order.
 *   P10 the class does not re-register the factory (no constructor / inject).
 *
 * @module dsh-memory/test/loop
 */

import assert from 'node:assert/strict'
import test from 'node:test'
import { HologramAgentLoop, promoteSnapshotSections } from '../lib/loop.js'

/** Build a user message shaped like a snapshot-style injector emits. */
function snapshotMessage(text, kind = 'memory') {
  return {
    role: 'user',
    content: [],
    source: { kind, form: 'snapshot', sections: [{ name: kind, text }] },
  }
}

/** Build a plain user message with real content. */
function plainMessage(text) {
  return { role: 'user', content: [{ type: 'text', text }], source: { kind: 'user' } }
}

/** A minimal decision carrying an assembly with one existing section. */
function decisionWith(messages, sections = [{ name: 'base', text: 'base prompt' }]) {
  return { kind: 'enter', messages, assembly: { sections, variables: {}, tools: [] } }
}

test('P1: a pure snapshot carrier is promoted into assembly.sections', () => {
  const decision = decisionWith([plainMessage('what did I decide?'), snapshotMessage('note alpha')])
  const out = promoteSnapshotSections(decision)

  assert.equal(out.messages.length, 1)
  assert.deepEqual(out.messages[0].content, [{ type: 'text', text: 'what did I decide?' }])
  assert.equal(out.assembly.sections.length, 2)
  const promoted = out.assembly.sections[1]
  assert.equal(promoted.text, 'note alpha')
  assert.ok(promoted.name.startsWith('memory'))
})

test('P2: the input decision is not mutated', () => {
  const original = decisionWith([snapshotMessage('note alpha')])
  const before = structuredClone(original)
  promoteSnapshotSections(original)
  assert.deepEqual(original, before)
})

test('P3: the promoted section opts out of interpolation', () => {
  const out = promoteSnapshotSections(decisionWith([snapshotMessage('literal {{not-a-var}} here')]))
  assert.equal(out.assembly.sections[1].interpolate, false)
})

test('P4a: a carrier whose content equals its sections IS promoted', () => {
  // The old P4 asserted the opposite for every message carrying content, on the
  // assumption that "content blocks present" means "the plugin wants the user to
  // see this". That assumption is FALSE for the only producer that matters here:
  // `lib/index.js:932` always injects exactly ONE text block whose text is
  // `sections[0].text` verbatim — content and sections are the same string. So
  // the old rule (`content non-empty ⇒ reject`) made `promoteSnapshotSections` a
  // permanent no-op on the real recall path and left recall in user/message
  // history, which is the bug this pair of tests exists to pin.
  const aligned = {
    role: 'user',
    content: [{ type: 'text', text: 'recalled note' }],
    source: { kind: 'memory', form: 'snapshot', sections: [{ name: 'memory', text: 'recalled note' }] },
  }
  const out = promoteSnapshotSections(decisionWith([aligned]))
  assert.equal(out.messages.length, 0, `content == sections must be promoted; got ${out.messages.length} message(s)`)
  assert.equal(out.assembly.sections.length, 2, `expected base + promoted; got ${out.assembly.sections.length}`)
  assert.equal(
    out.assembly.sections[1].text,
    'recalled note',
    `promoted text must be the content text unchanged; got ${JSON.stringify(out.assembly.sections[1].text)}`,
  )
})

test('P4b: a carrier whose content differs from its sections is NOT promoted', () => {
  // The old P4 used 'visible' vs 'hidden' — content != sections — which is the
  // side that must keep its hands off. That is exactly why it was green on the
  // broken commit: it asserted the correct behaviour for the wrong reason and
  // never covered the case that actually occurs (`content == sections`). It is
  // kept here, correctly named, as one half of the pair.
  const drifted = {
    role: 'user',
    content: [{ type: 'text', text: 'visible' }],
    source: { kind: 'memory', form: 'snapshot', sections: [{ name: 'memory', text: 'hidden' }] },
  }
  const out = promoteSnapshotSections(decisionWith([drifted]))
  assert.equal(out.messages.length, 1, `content != sections must stay in history; got ${out.messages.length}`)
  assert.equal(out.assembly.sections.length, 1, `no section may be added; got ${out.assembly.sections.length}`)
})

test('P4c: P4a and P4b are decided by TEXT, not by "has content at all"', () => {
  // One decision holding both carriers: if the implementation matched on the
  // mere presence of content, both would land on the same side and the
  // messages/sections counts below could not both hold.
  const aligned = {
    role: 'user',
    content: [{ type: 'text', text: 'recalled note' }],
    source: { kind: 'memory', form: 'snapshot', sections: [{ name: 'memory', text: 'recalled note' }] },
  }
  const drifted = {
    role: 'user',
    content: [{ type: 'text', text: 'visible' }],
    source: { kind: 'memory', form: 'snapshot', sections: [{ name: 'memory', text: 'hidden' }] },
  }
  const out = promoteSnapshotSections(decisionWith([aligned, drifted]))
  assert.deepEqual(out.messages, [drifted], 'only the mismatching carrier may survive')
  assert.equal(out.assembly.sections.length, 2, `only the matching carrier may be promoted; got ${out.assembly.sections.length}`)
})

test('P5: a non-snapshot message is not promoted', () => {
  const runtime = {
    role: 'user',
    content: [],
    source: { kind: 'runtime-context', form: 'inline', sections: [{ name: 'x', text: 'y' }] },
  }
  const out = promoteSnapshotSections(decisionWith([runtime]))
  assert.equal(out.messages.length, 1)
  assert.equal(out.assembly.sections.length, 1)
})

test('P6: a name collision is suffixed, never dropped', () => {
  const out = promoteSnapshotSections(
    decisionWith([snapshotMessage('note', 'base')], [{ name: 'base', text: 'base prompt' }]),
  )
  assert.equal(out.assembly.sections.length, 2)
  const names = out.assembly.sections.map((section) => section.name)
  assert.equal(new Set(names).size, names.length, 'section names must stay unique')
  assert.equal(out.assembly.sections[1].text, 'note')
})

test('P7: a reject decision passes through untouched', () => {
  const reject = { kind: 'reject', reason: 'nope' }
  assert.equal(promoteSnapshotSections(reject), reject)
})

test('P8: a decision without an assembly passes through untouched', () => {
  const bare = { kind: 'enter', messages: [snapshotMessage('note')] }
  assert.equal(promoteSnapshotSections(bare), bare)
})

test('P9: non-promoted messages keep their order', () => {
  const out = promoteSnapshotSections(
    decisionWith([plainMessage('first'), snapshotMessage('note'), plainMessage('second')]),
  )
  assert.deepEqual(
    out.messages.map((message) => message.content[0].text),
    ['first', 'second'],
  )
})

test('P10: the subclass does not re-declare the factory or its inject list', () => {
  // A second `setFactory` registration throws at startup, and re-declaring
  // `inject` would pull a duplicate AgentLoop into the container. Both are
  // avoided by not defining a constructor or static inject at all.
  assert.equal(Object.prototype.hasOwnProperty.call(HologramAgentLoop, 'inject'), false)
  const source = HologramAgentLoop.prototype.constructor.toString()
  assert.equal(source.includes('constructor'), false, 'subclass must not define a constructor')
  assert.equal(typeof HologramAgentLoop.prototype.prepare, 'function')
})

// ─────────────────────────────────────────────────────────────────────────
// S1–S7 · the two canonical spellings, and the ones that must not be touched
// ─────────────────────────────────────────────────────────────────────────
//
// Why this block exists: every test above builds its snapshot carrier with
// `content: []`. That is a shape NO real producer emits — `lib/index.js:932`
// always attaches exactly one `{ type: 'text' }` block whose text is
// `sections[0].text` verbatim. So the whole suite was green over a code path
// that never runs in production, and `promoteSnapshotSections` was a no-op on
// every real recall. The rule under test is three-way:
//
//   content == sections (either joining convention)  → PROMOTE, moving the text
//   content != sections                              → leave it in history
//
// The invariant is "move, don't rewrite": the promoted section text must be
// *identical* to the text the model would otherwise have read out of the
// message content, so these tests can tell a relocation from a silent rewrite.
//
// ★ Every negative case below carries a POSITIVE CONTROL in the same decision:
// a carrier of the same shape that *must* be promoted. Without the control a
// negative assertion is satisfied by the old "content non-empty ⇒ reject" rule
// alone, so it would be green on the broken commit and prove nothing. With it,
// the assertion fails unless the implementation is comparing the two texts.

/** A user message whose content and sections are the SAME single text. */
function carrier(text, kind = 'memory') {
  return {
    role: 'user',
    content: [{ type: 'text', text }],
    source: { kind, form: 'snapshot', sections: [{ name: kind, text }] },
  }
}

/**
 * A carrier whose N sections are rendered into ONE content block.
 *
 * The name states the shape: ONE text block. It models the two joining
 * conventions ('\n\n' and '') on that single block, which is what
 * `lib/index.js:932` actually emits.
 *
 * ★ This helper was previously called `multiCarrier` while producing a single
 * block, and that name is exactly what let the V2 bug (`if (blocks.length > 1)
 * return null`) pass untouched: S2a/S2b read as multi-block coverage while
 * exercising none of it. A helper whose name overstates its shape is worse than
 * a missing test, because it looks like coverage. Real multi-block carriers come
 * from `trueMultiCarrier` below and are exercised by S2c/S2d.
 * @param {string[]} texts one entry per section
 * @param {'glued'|'spaced'} convention how the sections were concatenated
 */
function singleBlockCarrier(texts, convention = 'spaced', kind = 'memory') {
  const joined = convention === 'glued' ? texts.join('') : texts.join('\n\n')
  return {
    role: 'user',
    content: [{ type: 'text', text: joined }],
    source: { kind, form: 'snapshot', sections: texts.map((text, i) => ({ name: `${kind}-${i}`, text })) },
  }
}

/**
 * 产出：N 个 text block，每个 block 一个 section 的文本（rendered = texts.join('')）。
 * 这不是本插件产出的形状，是"其它 producer 逐块发文本"的形状；只用来证明多块路径有牙。
 * 注意：真多块时 rendered 恒为 glued 拼法，没有 spaced 变体 —— spaced 只由单块承载。
 * @param {string[]} texts one entry per block AND per section
 * @param {string} kind source kind
 */
function trueMultiCarrier(texts, kind = 'memory') {
  return {
    role: 'user',
    content: texts.map((text) => ({ type: 'text', text })),
    source: { kind, form: 'snapshot', sections: texts.map((text, i) => ({ name: `${kind}-${i}`, text })) },
  }
}

/** Readable "expected vs actual" rendering for the assertion messages. */
const show = (value) => JSON.stringify(value)

test('S1: single block == single section is promoted, text byte-identical', () => {
  const out = promoteSnapshotSections(decisionWith([plainMessage('what did I decide?'), carrier('note alpha')]))
  assert.equal(
    out.messages.length,
    1,
    `the carrier must leave messages (expected 1 remaining, got ${out.messages.length})`,
  )
  assert.equal(
    out.assembly.sections.length,
    2,
    `expected base + promoted section = 2, got ${out.assembly.sections.length}`,
  )
  const promoted = out.assembly.sections[1]
  assert.equal(
    promoted.text,
    'note alpha',
    `promoted text must be the carrier text unchanged; expected ${show('note alpha')}, got ${show(promoted.text)}`,
  )
})

test('S2a: single content block carrying N sections ("\\n\\n" convention) is promoted', () => {
  const out = promoteSnapshotSections(decisionWith([singleBlockCarrier(['a', 'b'], 'spaced')]))
  assert.equal(
    out.messages.length,
    0,
    `the spaced carrier must be promoted (expected 0 messages, got ${out.messages.length})`,
  )
  assert.equal(
    out.assembly.sections.length,
    2,
    `expected base + promoted = 2 sections, got ${out.assembly.sections.length}`,
  )
  assert.equal(
    out.assembly.sections[1].text,
    'a\n\nb',
    `promoted text must equal the content text exactly (move, not rewrite); expected ${show('a\n\nb')}, got ${show(out.assembly.sections[1].text)}`,
  )
})

test('S2b: single content block carrying N sections ("" glued convention) is promoted', () => {
  const out = promoteSnapshotSections(decisionWith([singleBlockCarrier(['a', 'b'], 'glued')]))
  assert.equal(
    out.messages.length,
    0,
    `the glued carrier must be promoted (expected 0 messages, got ${out.messages.length})`,
  )
  assert.equal(
    out.assembly.sections.length,
    2,
    `expected base + promoted = 2 sections, got ${out.assembly.sections.length}`,
  )
  assert.equal(
    out.assembly.sections[1].text,
    'ab',
    `promoted text must equal the content text exactly; expected ${show('ab')}, got ${show(out.assembly.sections[1].text)}`,
  )
})

test('S2c: two content blocks == two sections (glued) is promoted', () => {
  const msg = trueMultiCarrier(['a', 'b'])   // 2 blocks, rendered='ab'
  const out = promoteSnapshotSections(decisionWith([msg]))
  assert.equal(out.messages.length, 0, `two blocks == two sections must be promoted; got ${out.messages.length} message(s)`)
  assert.equal(out.assembly.sections[1].text, 'ab', `promoted text must be the rendered content; got ${JSON.stringify(out.assembly.sections[1].text)}`)
})

test('S2d: two content blocks != sections is NOT promoted (control: the match is)', () => {
  // rendered = 'ab' (glued), while the single section says 'a\n\nb' — neither
  // canonical join matches, so this must stay in history. The control beside it
  // is the same two blocks with matching sections, which must be promoted.
  const drifted = {
    ...trueMultiCarrier(['a', 'b']),
    source: { kind: 'memory', form: 'snapshot', sections: [{ name: 'm0', text: 'a\n\nb' }] },
  }
  const control = trueMultiCarrier(['a', 'b'])
  const out = promoteSnapshotSections(decisionWith([control, drifted]))
  assert.equal(out.messages.length, 1, `only the drifted one may stay; got ${out.messages.length}`)
  assert.equal(out.messages[0], drifted, 'the surviving message must be the drifted one')
})

test('S3: single content block carrying N sections != those sections is NOT promoted (control: the match is)', () => {
  // Sections say "a"+"b", the content block says "zzz": editing the text would
  // not be a move, so this one must stay in history — while the matching
  // carrier beside it must go. The two must be told apart by CONTENT, not by
  // "does it carry content at all".
  const drifted = {
    role: 'user',
    content: [{ type: 'text', text: 'zzz' }],
    source: {
      kind: 'memory',
      form: 'snapshot',
      sections: [{ name: 'memory-0', text: 'a' }, { name: 'memory-1', text: 'b' }],
    },
  }
  const control = singleBlockCarrier(['a', 'b'], 'spaced')
  const out = promoteSnapshotSections(decisionWith([control, drifted]))
  assert.equal(
    out.messages.length,
    1,
    `only the drifted carrier may stay (expected 1 message, got ${out.messages.length})`,
  )
  assert.equal(out.messages[0], drifted, 'the surviving message must be the drifted carrier itself')
  assert.equal(
    out.assembly.sections.length,
    2,
    `only the control may be promoted (expected 2 sections, got ${out.assembly.sections.length})`,
  )
  assert.equal(
    out.assembly.sections[1].text,
    'a\n\nb',
    `the promoted text must come from the control; expected ${show('a\n\nb')}, got ${show(out.assembly.sections[1].text)}`,
  )
})

test('S4: single block != single section is NOT promoted (control: the match is)', () => {
  const drifted = {
    role: 'user',
    content: [{ type: 'text', text: 'content says this' }],
    source: { kind: 'memory', form: 'snapshot', sections: [{ name: 'memory', text: 'sections say that' }] },
  }
  const control = carrier('note alpha')
  const out = promoteSnapshotSections(decisionWith([control, drifted]))
  assert.equal(out.messages.length, 1, `only the drifted carrier may stay; got ${out.messages.length} messages`)
  assert.equal(out.messages[0], drifted, 'the surviving message must be the drifted carrier itself')
  assert.equal(out.assembly.sections.length, 2, `only the control may be promoted; got ${out.assembly.sections.length} sections`)
  assert.equal(
    out.assembly.sections[1].text,
    'note alpha',
    `promoted text must be the control's; expected ${show('note alpha')}, got ${show(out.assembly.sections[1].text)}`,
  )
})

test('S5: empty content (legacy carrier) is promoted — regression, with its real-world twin', () => {
  // Two carriers: the legacy `content: []` shape (which the old code did handle)
  // and the shape every real producer emits (which it did not). Both must be
  // promoted, so this doubles as the regression pin for the old path AND as the
  // minimal reproduction of the production no-op.
  const out = promoteSnapshotSections(decisionWith([snapshotMessage('note alpha'), carrier('note beta')]))
  assert.equal(
    out.messages.length,
    0,
    `both carriers must be promoted (expected 0 messages, got ${out.messages.length})`,
  )
  assert.deepEqual(
    out.assembly.sections.map((section) => section.text),
    ['base prompt', 'note alpha', 'note beta'],
    `expected the legacy text first, then the real-world text; got ${show(out.assembly.sections.map((s) => s.text))}`,
  )
})

test('S6: runtime-context shape (prefix in content, absent from sections) is NOT promoted', () => {
  // The stock loop prepends a fixed sentence to the content and keeps `sections`
  // as the raw contributions, so the two can never be equal. Promoting it would
  // delete that preamble, so it must pass through — the control carrier in the
  // same decision proves the comparison is on text, not on "has content".
  const runtime = {
    role: 'user',
    content: [
      {
        type: 'text',
        text: 'Current runtime context. This snapshot supersedes earlier runtime-context snapshots.\n\ncwd /tmp',
      },
    ],
    source: { kind: 'runtime-context', form: 'snapshot', sections: [{ name: 'runtime-context', text: 'cwd /tmp' }] },
  }
  const control = carrier('cwd /tmp', 'runtime-context')
  const out = promoteSnapshotSections(decisionWith([control, runtime]))
  assert.equal(out.messages.length, 1, `runtime-context must stay in history; got ${out.messages.length} messages`)
  assert.equal(out.messages[0], runtime, 'the surviving message must be the runtime-context snapshot itself')
  assert.equal(out.assembly.sections.length, 2, `only the control may be promoted; got ${out.assembly.sections.length} sections`)
  assert.equal(
    out.assembly.sections[1].text,
    'cwd /tmp',
    `promoted text must be the control's; expected ${show('cwd /tmp')}, got ${show(out.assembly.sections[1].text)}`,
  )
})

test('S7: a non-text block means NOT promoted (control: the text-only one is)', () => {
  const imageCarrier = {
    role: 'user',
    content: [{ type: 'image', text: 'note alpha' }],
    source: { kind: 'memory', form: 'snapshot', sections: [{ name: 'memory', text: 'note alpha' }] },
  }
  const badText = {
    role: 'user',
    content: [{ type: 'text', text: 42 }],
    source: { kind: 'memory', form: 'snapshot', sections: [{ name: 'memory', text: '42' }] },
  }
  const control = carrier('note alpha')
  const out = promoteSnapshotSections(decisionWith([control, imageCarrier, badText]))
  assert.equal(out.messages.length, 2, `only the text-only control may be promoted; got ${out.messages.length} messages`)
  assert.equal(out.messages[0], imageCarrier, 'the image carrier must survive')
  assert.equal(out.messages[1], badText, 'the non-string-text carrier must survive')
  assert.equal(out.assembly.sections.length, 2, `only the control may be promoted; got ${out.assembly.sections.length} sections`)
  assert.equal(
    out.assembly.sections[1].text,
    'note alpha',
    `promoted text must be the control's; expected ${show('note alpha')}, got ${show(out.assembly.sections[1].text)}`,
  )
})