local M = {}

-- Get current file context
function M.get_file_context()
  return {
    filepath = vim.fn.expand('%:p'),
    filename = vim.fn.expand('%:t'),
    filetype = vim.bo.filetype,
    line_count = vim.api.nvim_buf_line_count(0)
  }
end

-- Detect and extract visual selection
function M.get_selection_info(range_given, line1, line2)
  local selection = nil
  if range_given then
    -- Command called with range
    selection = {
      start_line = line1,
      end_line = line2,
      text = table.concat(vim.api.nvim_buf_get_lines(0, line1 - 1, line2, false), '\n')
    }
  elseif vim.fn.mode() == 'v' or vim.fn.mode() == 'V' then
    -- Visual mode selection
    local start_pos = vim.fn.getpos("'<")
    local end_pos = vim.fn.getpos("'>")
    selection = {
      start_line = start_pos[2],
      end_line = end_pos[2],
      text = table.concat(vim.api.nvim_buf_get_lines(0, start_pos[2] - 1, end_pos[2], false), '\n')
    }
  end
  return selection
end

-- Build prompt with context
function M.build_prompt(user_input, file_context, selection, is_edit_mode, diagnostic_info)
  local prompt_parts = {}

  -- Diagnostic fix mode instruction
  if diagnostic_info then
    table.insert(prompt_parts,
      "DIAGNOSTIC FIX MODE: Use your Edit tool to fix the following diagnostic issues in the code. Make precise fixes to resolve the specific problems listed.")
    table.insert(prompt_parts, diagnostic_info)
  elseif is_edit_mode then
    -- Edit mode instruction
    table.insert(prompt_parts,
      "EDIT MODE: Return ONLY the modified code with no explanations, markdown formatting, or additional text. Any explanations should be included as code comments within the code itself. Do not surround the code with backticks.")
  end

  -- File context
  table.insert(prompt_parts, string.format("File: %s (%s)", file_context.filename, file_context.filetype))

  -- Selection context if present
  if selection then
    table.insert(prompt_parts, string.format("Selected lines %d-%d:", selection.start_line, selection.end_line))
    table.insert(prompt_parts, "```" .. file_context.filetype)
    table.insert(prompt_parts, selection.text)
    table.insert(prompt_parts, "```")
  end

  -- User request
  table.insert(prompt_parts, "Request: " .. user_input)

  return table.concat(prompt_parts, '\n\n')
end

-- Execute claude command
function M.execute_claude(prompt, callback)
  -- Alternative 1: Use vim.system (Neovim 0.10+) - cleaner, no shell escaping needed
  vim.system({ 'claude', '-p', prompt }, {
    text = true
  }, function(result)
    vim.schedule(function()
      if result.code == 0 then
        if callback then callback(result.stdout) end
      else
        vim.notify("Claude error: " .. (result.stderr or "Unknown error"), vim.log.levels.ERROR)
      end
    end)
  end)
end

-- Execute claude command with tool permissions for diagnostic fixing
function M.execute_claude_with_tools(prompt, callback)
  vim.system({ 'claude', '--allowedTools=Edit,Read', '-p', prompt }, {
    text = true
  }, function(result)
    vim.schedule(function()
      if result.code == 0 then
        if callback then callback(result.stdout) end
      else
        vim.notify("Claude error: " .. (result.stderr or "Unknown error"), vim.log.levels.ERROR)
      end
    end)
  end)
end

-- Replace selection with new content
function M.replace_selection(selection, new_content)
  local lines = vim.split(new_content, '\n')
  vim.api.nvim_buf_set_lines(0, selection.start_line - 1, selection.end_line, false, lines)
end

-- Check if claude binary exists
function M.claude_available()
  return vim.fn.executable('claude') == 1
end

return M