-- Contact form configuration and logic
local validate = require("validate")
local json = require("json")

---@class ContactForm
local M = {}

---@class FormField
---@field name string
---@field label string
---@field type string
---@field required? boolean

---@class FormConfig
---@field fields FormField[]
---@field successMessage string

---@class FormState
---@field [string] string

---@class FormValidation
---@field valid boolean
---@field errors table<string, string>

---@class SubmitResult
---@field success boolean
---@field message? string
---@field errors? table<string, string>
---@field data? FormState

-- Load config from JSON file
---@type FormConfig
M.config = json.load("contact_form.json")

-- Create initial empty form state
---@return FormState
function M.createInitialState()
  local state = {}
  for _, field in ipairs(M.config.fields) do
    state[field.name] = ""
  end
  return state
end

-- Validate the contact form
---@param formValues FormState
---@return FormValidation
function M.validate(formValues)
  local errors = {}
  local emailPattern = "^[^%s@]+@[^%s@]+%.[^%s@]+$"

  for _, field in ipairs(M.config.fields) do
    local value = formValues[field.name]
    value = value and string.gsub(value, "^%s*(.-)%s*$", "%1") or ""

    if field.required and value == "" then
      errors[field.name] = field.label .. " is required"
    elseif field.type == "email" and value ~= "" then
      if not string.match(value, emailPattern) then
        errors[field.name] = "Enter a valid email address"
      end
    end
  end

  return { valid = next(errors) == nil, errors = errors }
end

-- Handle form submission
---@param formValues FormState
---@return SubmitResult
function M.handleSubmit(formValues)
  local validation = M.validate(formValues)

  if not validation.valid then
    return {
      success = false,
      errors = validation.errors
    }
  end

  log("Contact form submitted: " .. (formValues.email or "unknown"))

  return {
    success = true,
    message = M.config.successMessage,
    data = formValues
  }
end

return M