local M = {}

local function get_fb_interface(var_type)
  local fb_parser = require("scl.fb_parser")
  local clean_type = var_type:gsub('"', '')

  if fb_parser.get_cache_count() == 0 then
    local ws = require("scl.workspace_types")
    ws.scan_project_fbs(vim.api.nvim_get_current_buf())
  end

  return fb_parser.get_fb_interface(clean_type)
end

local function is_fb_type(var_type)
  local fb_parser = require("scl.fb_parser")
  local clean_type = var_type:gsub('"', '')

  if fb_parser.get_cache_count() == 0 then
    local ws = require("scl.workspace_types")
    ws.scan_project_fbs(vim.api.nvim_get_current_buf())
  end

  return fb_parser.is_fb_type(clean_type)
end

local function get_known_variables(bufnr)
  local scl_vars = require("scl.variables")
  local variables = scl_vars.extract_variables(bufnr)
  local known = {}
  for _, v in ipairs(variables) do
    known[v.name] = true
  end
  return known
end

local function get_variable_type(var_name, bufnr)
  local scl_vars = require("scl.variables")
  return scl_vars.get_variable_type(var_name, bufnr)
end

function M.fill_multiline_params()
  local bufnr = vim.api.nvim_get_current_buf()
  local cursor = vim.api.nvim_win_get_cursor(0)
  local row = cursor[1]
  local col = cursor[2]

  local line = vim.api.nvim_get_current_line()
  local line_before_cursor = line:sub(1, col)

  local known_vars = get_known_variables(bufnr)

  local fb_name = nil
  local fb_prefix = ""

  local prefix, var_name = line_before_cursor:match("(#?)([%w_]+)%s*%(%s*$")
  if var_name and known_vars[var_name] then
    fb_prefix = prefix or ""
    fb_name = var_name
  end

  if not fb_name then
    prefix, var_name = line_before_cursor:match("(#?)([%w_]+)%s*%([^)]-,%s*$")
    if var_name and known_vars[var_name] then
      fb_prefix = prefix or ""
      fb_name = var_name
    end
  end

  if not fb_name then
    vim.notify("No FB instance found before cursor", vim.log.levels.WARN)
    return
  end

  local var_type = get_variable_type(fb_name, bufnr)
  if not var_type then
    vim.notify("Cannot find type for: " .. fb_name, vim.log.levels.WARN)
    return
  end

  local clean_type = var_type:gsub('"', '')
  if not is_fb_type(clean_type) then
    vim.notify(clean_type .. " is not an FB/Function type", vim.log.levels.WARN)
    return
  end

  local fb_interface = get_fb_interface(clean_type)
  if not fb_interface then
    vim.notify("Cannot get interface for: " .. clean_type, vim.log.levels.WARN)
    return
  end

  local params = {}
  for _, inp in ipairs(fb_interface.inputs or {}) do
    table.insert(params, inp.name .. " := ")
  end
  for _, inout in ipairs(fb_interface.inouts or {}) do
    table.insert(params, inout.name .. " := ")
  end
  for _, out in ipairs(fb_interface.outputs or {}) do
    table.insert(params, out.name .. " => ")
  end

  if #params == 0 then
    vim.notify("No parameters found for: " .. clean_type, vim.log.levels.WARN)
    return
  end

  local indent = line:match("^%s*") or ""

  local continuation_indent = indent .. string.rep(" ", #fb_name + 2)

  local lines_to_insert = {}

  local first_line = indent .. fb_prefix .. fb_name .. "(" .. params[1] .. ","
  table.insert(lines_to_insert, first_line)

  for i = 2, #params do
    local p = params[i]
    local closing = (i == #params) and ");" or ","
    local line_content = continuation_indent .. p .. closing
    table.insert(lines_to_insert, line_content)
  end

  vim.api.nvim_buf_set_lines(bufnr, row - 1, row, false, lines_to_insert)

  local new_cursor_row = row
  local new_cursor_col = #indent + #fb_prefix + #fb_name + 1 + #params[1]

  vim.api.nvim_win_set_cursor(0, { new_cursor_row, new_cursor_col })
end

local function is_inside_fb_call(bufnr, cursor_row, cursor_col)
  local function get_line_text(rownum)
    return vim.api.nvim_buf_get_lines(bufnr, rownum - 1, rownum, false)[1] or ""
  end

  local known_vars = get_known_variables(bufnr)

  local paren_depth = 0
  local found_fb_call_start = false

  for i = cursor_row, 1, -1 do
    local line = get_line_text(i)
    local line_to_cursor = (i == cursor_row) and line:sub(1, cursor_col) or line

    for j = #line_to_cursor, 1, -1 do
      local char = line_to_cursor:sub(j, j)
      if char == ")" then
        paren_depth = paren_depth + 1
      elseif char == "(" then
        if paren_depth > 0 then
          paren_depth = paren_depth - 1
        else
          local before_paren = line_to_cursor:sub(1, j - 1)
          local var_match = before_paren:match("#?([%w_]+)%s*$")
          if var_match and known_vars[var_match] then
            return true
          end
          found_fb_call_start = true
          break
        end
      end
    end

    if found_fb_call_start then
      break
    end

    if line:match("^%s*END_") or line:match("^%s*BEGIN") then
      break
    end
  end

  return false
end

function M.jump_to_next_param()
  local cursor = vim.api.nvim_win_get_cursor(0)
  local row = cursor[1]
  local col = cursor[2]

  local bufnr = vim.api.nvim_get_current_buf()

  if not is_inside_fb_call(bufnr, row, col) then
    return false
  end

  local total_lines = vim.api.nvim_buf_line_count(bufnr)

  local function get_line_text(rownum)
    return vim.api.nvim_buf_get_lines(bufnr, rownum - 1, rownum, false)[1] or ""
  end

  local function find_next_param_on_line(start_row)
    for i = start_row, total_lines do
      local line = get_line_text(i)
      local param_match = line:match("[%w_]+%s*:=") or line:match("[%w_]+%s*=>")
      if param_match then
        local op_end = line:find(":=") or line:find("=>")
        vim.api.nvim_win_set_cursor(0, { i, op_end + 2 })
        return true
      end
      if line:match("%)") then
        break
      end
    end
    return false
  end

  local current_line = get_line_text(row)
  local text_after_cursor = current_line:sub(col + 1)

  local next_param = text_after_cursor:match("([%w_]+)%s*:=") or text_after_cursor:match("([%w_]+)%s*=>")
  if next_param then
    local op_end = text_after_cursor:find(":=") or text_after_cursor:find("=>")
    local new_col = col + op_end + 2
    vim.api.nvim_win_set_cursor(0, { row, new_col })
    return true
  end

  if not find_next_param_on_line(row + 1) then
    local all_params = {}
    local all_text = ""
    for i = row, total_lines do
      local l = get_line_text(i)
      all_text = all_text .. l .. "\n"
      if l:match("%)") then
        break
      end
    end
    for param in all_text:gmatch("([%w_]+)%s*:=") do
      table.insert(all_params, param)
    end
    for param in all_text:gmatch("([%w_]+)%s*=>") do
      table.insert(all_params, param)
    end

    if #all_params > 0 then
      vim.api.nvim_feedkeys("> ", "m", false)
      return true
    end
  else
    return true
  end

  return false
end

return M