#!/usr/bin/env nu
# Check for malformed closing code fences in markdown files
# CommonMark spec violation: Closing fences should be ``` without language specifiers

def main [] {
  # Find all markdown files (excluding ignored directories)
  let md_files = (
    glob **/*.md
    | where {|f| not ($f | str contains ".git") }
    | where {|f| not ($f | str contains "target") }
    | where {|f| not ($f | str contains "node_modules") }
    | where {|f| not ($f | str contains ".coder") }
    | where {|f| not ($f | str contains ".claude") }
    | where {|f| not ($f | str contains ".wrks") }
  )

  mut total_issues = 0
  mut files_with_issues = []

  for file in $md_files {
    let issues = (check_file $file)
    if ($issues | length) > 0 {
      $total_issues = $total_issues + ($issues | length)
      $files_with_issues = ($files_with_issues | append {file: $file, issues: $issues})
    }
  }

  if $total_issues > 0 {
    print $"❌ Found ($total_issues) malformed closing fence\(s\) in ($files_with_issues | length) file\(s\):\n"

    for item in $files_with_issues {
      print $"  ($item.file):"
      for issue in $item.issues {
        print $"    Line ($issue.line): ($issue.content)"
      }
    }

    print "\nFix: Remove language specifiers from closing fences (should be just ```)"
    exit 1
  } else {
    print "✅ No malformed closing fences found"
    exit 0
  }
}

def check_file [file: string] {
  mut issues = []
  mut in_code_block = false
  mut line_num = 0

  for line in (open $file | lines) {
    $line_num = $line_num + 1

    # Check if line is a code fence
    let fence_match = ($line | parse --regex '^```(?P<lang>\w+)?\s*$')

    if ($fence_match | length) > 0 {
      if not $in_code_block {
        # Opening fence
        $in_code_block = true
      } else {
        # Closing fence
        let lang = ($fence_match | get 0.lang? | default "")
        if ($lang | str length) > 0 {
          # Malformed: has language on closing fence
          $issues = ($issues | append {line: $line_num, content: $line})
        }
        $in_code_block = false
      }
    }
  }

  $issues
}