local M = {}

-- Get diagnostics for a specific line range
function M.get_range_diagnostics(bufnr, start_line, end_line)
  local all_diagnostics = vim.diagnostic.get(bufnr or 0)
  local range_diagnostics = {}
  
  for _, diagnostic in ipairs(all_diagnostics) do
    -- Convert from 0-indexed to 1-indexed for user-facing line numbers
    local diag_line = diagnostic.lnum + 1
    if diag_line >= start_line and diag_line <= end_line then
      table.insert(range_diagnostics, diagnostic)
    end
  end
  
  return range_diagnostics
end

-- Format diagnostics for Claude prompt
function M.format_diagnostics_for_prompt(diagnostics)
  if #diagnostics == 0 then
    return "No diagnostics found in the selected range."
  end
  
  local severity_names = {
    [vim.diagnostic.severity.ERROR] = "ERROR",
    [vim.diagnostic.severity.WARN] = "WARNING", 
    [vim.diagnostic.severity.INFO] = "INFO",
    [vim.diagnostic.severity.HINT] = "HINT"
  }
  
  local formatted_lines = {}
  table.insert(formatted_lines, "Diagnostic Issues:")
  
  for _, diagnostic in ipairs(diagnostics) do
    local line_num = diagnostic.lnum + 1  -- Convert to 1-indexed
    local severity = severity_names[diagnostic.severity] or "UNKNOWN"
    local message = diagnostic.message:gsub("\n", " ")  -- Remove newlines from message
    
    table.insert(formatted_lines, string.format("Line %d: [%s] %s", line_num, severity, message))
  end
  
  return table.concat(formatted_lines, "\n")
end

-- Quick check if any diagnostics exist in range
function M.has_diagnostics(bufnr, start_line, end_line)
  local diagnostics = M.get_range_diagnostics(bufnr, start_line, end_line)
  return #diagnostics > 0
end

return M