harn-stdlib 0.8.25

// std/table - deterministic plain-text and Markdown table rendering.
import { ansi_truncate, ansi_visible_len } from "std/ansi"

type TableColumn = {key?: string, header?: string, align?: string, width?: int, max_width?: int}

type TableOptions = {
  columns?: list,
  headers?: list<string>,
  format?: string,
  max_cell_width?: int,
  header?: bool,
  empty?: string,
}

fn __table_text(value) -> string {
  if value == nil {
    return ""
  }
  let kind = type_of(value)
  if kind == "dict" || kind == "list" || kind == "set" {
    return json_stringify(value)
  }
  return to_string(value)
}

fn __table_cell(value, max_width) -> string {
  let normalized = replace(replace(__table_text(value), "\r", " "), "\n", "\\n")
  if max_width != nil && max_width > 0 {
    return ansi_truncate(normalized, max_width)
  }
  return normalized
}

fn __table_column_from(raw, idx, headers) {
  if type_of(raw) == "string" {
    return {key: raw, header: raw, align: "left", index: idx}
  }
  let col = raw ?? {}
  let key = col?.key ?? col?.name ?? col?.header ?? to_string(idx)
  let header = col?.header ?? (headers?[idx] ?? key)
  return {
    key: key,
    header: header,
    align: lowercase(col?.align ?? "left"),
    width: col?.width,
    max_width: col?.max_width,
    index: idx,
  }
}

fn __table_columns(rows, opts) {
  let options = opts ?? {}
  let headers = options?.headers ?? []
  var cols = []
  if type_of(options?.columns) == "list" && len(options.columns) > 0 {
    var idx = 0
    for raw in options.columns {
      cols = cols.push(__table_column_from(raw, idx, headers))
      idx += 1
    }
    return cols
  }
  if len(headers) > 0 {
    var hidx = 0
    for header in headers {
      cols = cols.push({key: to_string(hidx), header: header, align: "left", index: hidx})
      hidx += 1
    }
    return cols
  }
  let first = rows?[0]
  if type_of(first) == "dict" {
    for key in keys(first).sort() {
      cols = cols.push({key: key, header: key, align: "left", index: len(cols)})
    }
    return cols
  }
  if type_of(first) == "list" {
    var i = 0
    while i < len(first) {
      cols = cols.push({key: to_string(i), header: to_string(i), align: "left", index: i})
      i += 1
    }
  }
  return cols
}

fn __table_value(row, col) {
  if type_of(row) == "dict" {
    return row[col.key]
  }
  if type_of(row) == "list" {
    return row[col.index]
  }
  if col.index == 0 {
    return row
  }
  return nil
}

fn __table_matrix(rows, cols, opts) {
  let default_max = opts?.max_cell_width
  var matrix = []
  for row in rows ?? [] {
    var rendered = []
    for col in cols {
      let max_width = col?.max_width ?? default_max
      rendered = rendered.push(__table_cell(__table_value(row, col), max_width))
    }
    matrix = matrix.push(rendered)
  }
  return matrix
}

fn __table_widths(cols, matrix) {
  var widths = []
  var i = 0
  while i < len(cols) {
    let fixed = cols[i]?.width
    if fixed != nil && fixed > 0 {
      widths = widths.push(fixed)
      i += 1
      continue
    }
    var width = ansi_visible_len(cols[i]?.header ?? "")
    for row in matrix {
      width = max(width, ansi_visible_len(row[i] ?? ""))
    }
    widths = widths.push(width)
    i += 1
  }
  return widths
}

fn __table_pad(value, width, align) -> string {
  let text = value ?? ""
  let missing = width - ansi_visible_len(text)
  if missing <= 0 {
    return text
  }
  if align == "right" {
    return " ".repeat(missing) + text
  }
  if align == "center" {
    let left = floor(missing / 2)
    let right = missing - left
    return " ".repeat(left) + text + " ".repeat(right)
  }
  return text + " ".repeat(missing)
}

fn __table_render_row(cells, cols, widths) -> string {
  var out = []
  var i = 0
  while i < len(cols) {
    out = out.push(__table_pad(cells[i] ?? "", widths[i], cols[i]?.align ?? "left"))
    i += 1
  }
  return join(out, " | ")
}

fn __table_plain_separator(widths) -> string {
  var parts = []
  for width in widths {
    parts = parts.push("-".repeat(max(width, 3)))
  }
  return join(parts, "-+-")
}

fn __table_markdown_escape(value) -> string {
  return replace(value ?? "", "|", "\\|")
}

fn __table_markdown_row(cells, cols, widths) -> string {
  var out = []
  var i = 0
  while i < len(cols) {
    out = out.push(__table_markdown_escape(__table_pad(cells[i] ?? "", widths[i], cols[i]?.align ?? "left")))
    i += 1
  }
  return "| " + join(out, " | ") + " |"
}

fn __table_markdown_separator(cols, widths) -> string {
  var out = []
  var i = 0
  while i < len(cols) {
    let marks = "-".repeat(max(widths[i], 3))
    let align = cols[i]?.align ?? "left"
    let cell = if align == "right" {
      marks + ":"
    } else if align == "center" {
      ":" + marks + ":"
    } else {
      marks
    }
    out = out.push(cell)
    i += 1
  }
  return "| " + join(out, " | ") + " |"
}

fn __table_render_plain(cols, matrix, widths, show_header) -> string {
  var lines = []
  if show_header {
    let header_cells = cols.map({ col -> col?.header ?? col?.key ?? "" })
    lines = lines.push(__table_render_row(header_cells, cols, widths))
    lines = lines.push(__table_plain_separator(widths))
  }
  for row in matrix {
    lines = lines.push(__table_render_row(row, cols, widths))
  }
  return join(lines, "\n")
}

fn __table_render_markdown(cols, matrix, widths, show_header) -> string {
  var lines = []
  let header_cells = if show_header {
    cols.map({ col -> col?.header ?? col?.key ?? "" })
  } else {
    cols.map({ _col -> "" })
  }
  lines = lines.push(__table_markdown_row(header_cells, cols, widths))
  lines = lines.push(__table_markdown_separator(cols, widths))
  for row in matrix {
    lines = lines.push(__table_markdown_row(row, cols, widths))
  }
  return join(lines, "\n")
}

/** Render rows as a stable plain-text or Markdown table. */
pub fn render_table(rows: list, options: TableOptions = {}) -> string {
  let items = rows ?? []
  if len(items) == 0 {
    return options.empty ?? ""
  }
  let cols = __table_columns(items, options)
  if len(cols) == 0 {
    return options.empty ?? ""
  }
  let matrix = __table_matrix(items, cols, options ?? {})
  let widths = __table_widths(cols, matrix)
  let format = lowercase(options.format ?? "plain")
  let show_header = options.header ?? true
  if format == "markdown" || format == "md" {
    return __table_render_markdown(cols, matrix, widths, show_header)
  }
  return __table_render_plain(cols, matrix, widths, show_header)
}

/** Alias for `render_table(..., {format: "markdown"})`. */
pub fn render_markdown_table(rows: list, options: TableOptions = {}) -> string {
  let base = options ?? {}
  return render_table(rows, base + {format: "markdown"})
}

/** Render a dict as a two-column key/value table. */
pub fn render_kv_table(data: dict, options: TableOptions = {}) -> string {
  var rows = []
  for key in keys(data ?? {}).sort() {
    rows = rows.push({key: key, value: data[key]})
  }
  let base = options ?? {}
  let opts = base
    + {
    columns: [
      {key: "key", header: base?.key_header ?? "Key"},
      {key: "value", header: base?.value_header ?? "Value"},
    ],
  }
  return render_table(rows, opts)
}