module main

import arrays

interface Value {}

struct Params {
    email string
}

fn generate_params(s string) []Value {
    mut params := []Value{}
    params = arrays.concat(params, s)
    return params
}

fn generate_selector_params(p Params) []Value {
    mut params := []Value{}
    params = arrays.concat(params, p.email)
    return params
}

fn generate_local_params() []Value {
    s := '[email protected]'
    mut params := []Value{}
    params = arrays.concat(params, s)
    return params
}

fn generate_local_selector_params() []Value {
    p := Params{
        email: '[email protected]'
    }
    mut params := []Value{}
    params = arrays.concat(params, p.email)
    return params
}

struct OptionalParams {
    email ?string
}

fn generate_optional_params(p OptionalParams) []Value {
    mut params := []Value{}
    if email := p.email {
        params = arrays.concat(params, email)
    }
    return params
}

struct Statement {
}

struct Tx {
}

fn (mut s Statement) execute(params ...Value) !string {
    match params[0] {
        string {
            return params[0] as string
        }
        else {
            return error(typeof(params[0]).name)
        }
    }
}

fn (mut t Tx) prepare() !&Statement {
    return &Statement{}
}

fn (mut t Tx) execute(params ...Value) !string {
    mut stmt := t.prepare()!
    return stmt.execute(...params)!
}

fn test_interface_string_ref_arg() {
    params := generate_params('any_string')
    assert params == [Value('any_string')]
}

fn test_interface_string_ref_local() {
    params := generate_local_params()
    assert params == [Value('[email protected]')]
}

fn test_interface_string_ref_selector_arg() {
    params := generate_selector_params(Params{
        email: '[email protected]'
    })
    assert params == [Value('[email protected]')]
}

fn test_interface_string_ref_selector_local() {
    params := generate_local_selector_params()
    assert params == [Value('[email protected]')]
}

fn test_interface_string_ref_arg_from_option_unwrap_forwarded_through_variadic_call() {
    params := generate_optional_params(OptionalParams{
        email: '[email protected]'
    })
    mut tx := Tx{}
    got := tx.execute(...params) or { panic(err) }
    assert got == '[email protected]'
}