# fmt_lint_rules.ludic — L10: the rules themselves, over one file's text and its tokens
function lint_file(path: string, text: string) -> void {
  let ls = lt_lines(text)
  if lt_max_file > 0 and len(ls) > lt_max_file { lt_report(path, "max_file_lines", len(ls), `{len(ls)} lines (the limit is {lt_max_file})`) }
  lint_comments(path, ls)
  lex(text)
  if lt_one { lint_statements(path) }
  if lt_max_fn > 0 { lint_functions(path) }
}
function lint_comments(path: string, ls: []string) -> void {
  var run = 0
  var start = 0
  var code_seen = false
  var i = 0
  while i <= len(ls) {
    var is_c = false
    var blank = true
    if i < len(ls) {
      let w = lt_words_raw(ls[i])
      is_c = w == 1
      blank = w == 0
    }
    if is_c {
      if run == 0 { start = i }
      run += 1
    } else {
      if run > 0 {
        let header = not code_seen and start == 0
        let col = lt_indent(ls[start]) + 1
        if header and lt_max_header > 0 and run > lt_max_header { lt_report_at(path, "max_header_lines", start + 1, col, `the opening comment is {run} lines (the limit is {lt_max_header})`) }
        if not header and lt_max_comment > 0 and run > lt_max_comment { lt_report_at(path, "max_comment_lines", start + 1, col, `a comment of {run} lines (the limit is {lt_max_comment}): say why in a line or two; the story goes in the commit or docs/`) }
        run = 0
      }
      if not blank { code_seen = true }
    }
    i += 1
  }
}
# the spaces and tabs a line opens with
function lt_indent(line: string) -> int {
  var i = 0
  while i < len(line) and (line[i] == ' ' or line[i] == 9) { i += 1 }
  return i
}
# a token's 1-based byte column on its line
function lt_tok_col(i: int) -> int { return tk_start[i] - linestart[tk_line[i]] + 1 }
# 0 a blank line, 1 a comment line, 2 code
function lt_words_raw(line: string) -> int {
  var i = 0
  while i < len(line) and (line[i] == ' ' or line[i] == 9) { i += 1 }
  if i >= len(line) { return 0 }
  if line[i] == '#' { return 1 }
  return 2
}
function lint_statements(path: string) -> void {
  var i = 0
  while i < ntok() {
    if tk_kind[i] == LT_OP and tok_len(i) == 1 and src[tk_start[i]] == ';' {
      let k = tk_kind[i + 1]
      if k != LT_NL and k != LT_COMMENT and k != LT_EOF { lt_report_at(path, "one_statement", tk_line[i] + 1, lt_tok_col(i + 1), "two statements on one line") }
    }
    i += 1
  }
}
function lint_functions(path: string) -> void {
  var i = 0
  while i < ntok() {
    if tk_kind[i] == LT_KW and (tok_text(i) == "function") {
      let end = lt_fn_end(i)
      if end >= 0 {
        let n = tk_line[end] - tk_line[i] + 1
        if n > lt_max_fn { lt_report_at(path, "max_function_lines", tk_line[i] + 1, lt_tok_col(i), `{lt_fn_name(i)} is {n} lines (the limit is {lt_max_fn})`) }
      }
    }
    i += 1
  }
}
function lt_fn_name(i: int) -> string {
  if i + 1 < ntok() { return string(tok_text(i + 1)) }
  return "a function"
}
# the token closing a function's body, or -1 for one with none (an extern)
function lt_fn_end(i: int) -> int {
  var j = i + 1
  var paren = 0
  var closed = false
  while j < ntok() {
    let k = tk_kind[j]
    if k == LT_OP and tok_len(j) == 1 {
      let c = src[tk_start[j]]
      if c == '(' { paren += 1 }
      if c == ')' {
        paren -= 1
        if paren == 0 { closed = true }
      }
      if c == '{' and paren == 0 and closed { return lt_close(j) }
    }
    if (k == LT_NL or k == LT_EOF) and paren == 0 and closed { return -1 }
    j += 1
  }
  return -1
}
function lt_close(open: int) -> int {
  var depth = 0
  var j = open
  while j < ntok() {
    if tk_kind[j] == LT_OP and tok_len(j) == 1 {
      let c = src[tk_start[j]]
      if c == '{' { depth += 1 }
      if c == '}' {
        depth -= 1
        if depth == 0 { return j }
      }
    }
    j += 1
  }
  return ntok() - 1
}