// ── A group's BetterChat style, and the voice made from one (phase 17) ─────
//
// D138 puts all twelve of BetterChat's group fields on a site-authored group,
// and D140 lets one styled group be the VOICE the module's own lines are said
// in. Both are pure text work, so they live here, without a database or a game:
//
//   validateStyle  what an operator typed → the twelve values BetterChat's own
//                  `chat group set` accepts, or one sentence per problem
//   voiceFormat    a style → the format string `chat.say` carries: BetterChat's
//                  markup with exactly one `{message}` in it
//
// Every value is TEXT, in the form BetterChat's setter parses — `true`/`false`,
// a decimal integer, a colour — because text is what the plugin compares the
// game's value against when it decides whether somebody edited a field by hand
// (§33.2). Two spellings of one value would be drift that never happened.

/** The longest a format may be (§33.4 reading 7). */
const FORMAT_MAX = 128

/** The longest a group's title may be. BetterChat has no limit; a chat line does. */
const TITLE_MAX = 64

/**
 * The twelve fields, by the name BetterChat's API takes, each with its type and
 * BetterChat 5.2.15's default. `Title`'s default is the group's own name in
 * brackets, so it is worked out in `defaults`.
 */
const FIELDS = [
  { name: 'Priority', type: 'int', min: -9999, max: 9999, default: '0' },
  { name: 'Title', type: 'title', default: null },
  { name: 'TitleColor', type: 'color', default: '#55aaff' },
  { name: 'TitleSize', type: 'size', default: '15' },
  { name: 'TitleHidden', type: 'bool', default: 'false' },
  { name: 'TitleHiddenIfNotPrimary', type: 'bool', default: 'false' },
  { name: 'UsernameColor', type: 'color', default: '#55aaff' },
  { name: 'UsernameSize', type: 'size', default: '15' },
  { name: 'MessageColor', type: 'color', default: 'white' },
  { name: 'MessageSize', type: 'size', default: '15' },
  { name: 'ChatFormat', type: 'format', default: '{Title} {Username}: {Message}' },
  { name: 'ConsoleFormat', type: 'format', default: '{Title} {Username}: {Message}' },
]

const FIELD_NAMES = FIELDS.map((f) => f.name)

/** BetterChat's defaults for a new group of this name — what the form starts from. */
function defaults(group) {
  const out = {}
  for (const f of FIELDS) out[f.name] = f.default
  out.Title = group === 'default' ? '[Player]' : `[${group}]`
  return out
}

function occurrences(text, needle) {
  return text.split(needle).length - 1
}

/**
 * One field's value as BetterChat's setter takes it, or a sentence.
 *
 * Colours are `#rrggbb` or a plain colour word (BetterChat's own default for a
 * message is `white`). A format holds `{Message}` EXACTLY once: without it every
 * line a member types is swallowed, and twice cannot be made into a voice,
 * whose line has one message.
 */
function checkField(field, raw) {
  const text = typeof raw === 'boolean' || typeof raw === 'number' ? String(raw) : typeof raw === 'string' ? raw.trim() : null
  if (text === null || /[\r\n]/.test(text)) return { error: `${field.name} must be text on one line` }

  switch (field.type) {
    case 'int': {
      if (!/^-?\d{1,4}$/.test(text)) return { error: `${field.name} must be a whole number from ${field.min} to ${field.max}` }
      return { value: String(Number(text)) }
    }
    case 'size': {
      if (!/^\d{1,2}$/.test(text) || Number(text) < 6 || Number(text) > 64) return { error: `${field.name} must be a size from 6 to 64` }
      return { value: String(Number(text)) }
    }
    case 'bool': {
      const lowered = text.toLowerCase()
      if (lowered !== 'true' && lowered !== 'false') return { error: `${field.name} must be true or false` }
      return { value: lowered }
    }
    case 'color': {
      if (/^#[0-9a-fA-F]{6}$/.test(text)) return { value: text.toLowerCase() }
      if (/^[a-z]{3,20}$/.test(text)) return { value: text }
      return { error: `${field.name} must be a colour like #ffaa55, or a colour word like white` }
    }
    case 'title': {
      if (!text.length || text.length > TITLE_MAX) return { error: `Title must be 1 to ${TITLE_MAX} characters` }
      // A brace would be read as a placeholder when the title is put into a line.
      if (/[{}]/.test(text)) return { error: 'Title cannot contain { or }' }
      return { value: text }
    }
    case 'format': {
      if (text.length > FORMAT_MAX) return { error: `${field.name} must be at most ${FORMAT_MAX} characters` }
      if (occurrences(text, '{Message}') !== 1) return { error: `${field.name} must contain {Message} exactly once` }
      return { value: text }
    }
    default:
      return { error: `${field.name} is not a field this site knows` }
  }
}

/**
 * An operator's style, checked whole. All twelve fields are required — a style
 * is the whole of a BetterChat group or nothing (D138), which is what keeps a
 * half-authored group from being a set of values nobody chose.
 *
 * Resolves `{ ok: true, fields }` with every value normalised, or
 * `{ ok: false, errors }`, one sentence per problem.
 */
function validateStyle(style) {
  if (!style || typeof style !== 'object' || Array.isArray(style)) {
    return { ok: false, errors: ['a chat style is an object of the twelve BetterChat fields'] }
  }

  const errors = []
  const fields = {}

  for (const key of Object.keys(style)) {
    if (!FIELD_NAMES.includes(key)) errors.push(`${key} is not a BetterChat group field`)
  }

  for (const field of FIELDS) {
    if (style[field.name] === undefined || style[field.name] === null) {
      errors.push(`${field.name} is missing`)
      continue
    }
    const checked = checkField(field, style[field.name])
    if (checked.error) errors.push(checked.error)
    else fields[field.name] = checked.value
  }

  return errors.length ? { ok: false, errors } : { ok: true, fields }
}

/** A colour as BetterChat's markup writes it: the hex without its `#`, or the word. */
function markupColor(color) {
  return String(color || 'white').replace(/^#/, '')
}

/**
 * The format a styled group's voice says a line in (D140), or null.
 *
 * Built from six of the twelve fields (§33.4 reading 5): the title, its colour
 * and size, the message's colour and size, and `ChatFormat`. The line has no
 * sender, so `{Username}` renders as nothing — and so does the `:` BetterChat's
 * own default puts after it, or every announcement would read `[Title] : …`.
 * `{Group}`, `{ID}`, `{Time}` and `{Date}` render as nothing for the same
 * reason. The plugin puts the words in for `{message}` and turns the markup into
 * the game's rich text.
 */
function voiceFormat(fields) {
  if (!fields || !fields.ChatFormat || occurrences(fields.ChatFormat, '{Message}') !== 1) return null

  const title =
    fields.TitleHidden === 'true'
      ? ''
      : `[#${markupColor(fields.TitleColor)}][+${fields.TitleSize || 15}]${fields.Title || ''}[/+][/#]`
  const message = `[#${markupColor(fields.MessageColor)}][+${fields.MessageSize || 15}]{message}[/+][/#]`

  // split/join rather than `replace`, whose replacement string treats `$&` and
  // friends as patterns — and a title is operator text.
  const format = fields.ChatFormat
    .replace(/\{Username\}\s*:?/g, '')
    .replace(/\{(Group|ID|Time|Date)\}/g, '')
    .split('{Title}').join(title)
    .split('{Message}').join(message)
    .replace(/\s{2,}/g, ' ')
    .trim()

  return occurrences(format, '{message}') === 1 ? format : null
}

module.exports = { FIELDS, FIELD_NAMES, FORMAT_MAX, TITLE_MAX, defaults, validateStyle, voiceFormat, checkField }