//! Integration tests for `help` and `help <command>` (H3).
//!
//! Covers:
//! - Parse layer: `help` → `Help { topic: None }`; `help insert`
//!   → `Help { topic: Some("insert") }`.
//! - App behaviour: the full `help` ends with the detail hint;
//!   `help <command>` renders that command's block (and every
//!   form sharing the entry word); `help types` renders the type
//!   reference; an unknown topic gets a friendly pointer back.

use crossterm::event::{KeyCode, KeyEvent, KeyEventKind, KeyModifiers};

use rdbms_playground::app::App;
use rdbms_playground::dsl::{parse_command, AppCommand, Command};
use rdbms_playground::event::AppEvent;

const fn key(code: KeyCode) -> AppEvent {
    AppEvent::Key(KeyEvent {
        code,
        modifiers: KeyModifiers::NONE,
        kind: KeyEventKind::Press,
        state: crossterm::event::KeyEventState::NONE,
    })
}

fn type_str(app: &mut App, s: &str) {
    for c in s.chars() {
        app.update(key(KeyCode::Char(c)));
    }
}

/// Submit `input` to a fresh app and collect all output text.
fn output_for(input: &str) -> Vec<String> {
    let mut app = App::new();
    type_str(&mut app, input);
    app.update(key(KeyCode::Enter));
    app.output.iter().map(|l| l.text.clone()).collect()
}

// =================================================================
// Parse layer
// =================================================================

#[test]
fn bare_help_parses_with_no_topic() {
    assert_eq!(
        parse_command("help").expect("parses"),
        Command::App(AppCommand::Help { topic: None }),
    );
}

#[test]
fn help_with_topic_captures_the_word() {
    assert_eq!(
        parse_command("help insert").expect("parses"),
        Command::App(AppCommand::Help {
            topic: Some("insert".to_string())
        }),
    );
}

#[test]
fn help_topic_is_a_single_word_multi_word_is_a_parse_error() {
    // Entry-word topics cover multi-word commands (`help create`),
    // so a second word is trailing junk, not a longer topic.
    assert!(parse_command("help foo bar").is_err());
}

// =================================================================
// App behaviour
// =================================================================

#[test]
fn full_help_lists_commands_and_ends_with_the_detail_hint() {
    let out = output_for("help");
    assert!(
        out.iter().any(|l| l == "Supported commands:"),
        "intro present: {out:?}",
    );
    assert!(
        out.iter().any(|l| l.contains("help <command>")),
        "detail-hint footer present: {out:?}",
    );
}

#[test]
fn help_insert_renders_the_insert_block() {
    let out = output_for("help insert");
    assert!(
        out.iter().any(|l| l.contains("insert into")),
        "insert help shown: {out:?}",
    );
    // Focused: it must NOT dump the whole list — the intro header
    // belongs to the full `help` only.
    assert!(
        !out.iter().any(|l| l == "Supported commands:"),
        "focused help omits the full-list intro: {out:?}",
    );
}

#[test]
fn help_create_covers_every_form_sharing_the_entry_word() {
    // `create` is the entry word for both the DSL `create table`
    // and the advanced SQL `CREATE TABLE` — `help create` shows
    // both blocks.
    let out = output_for("help create");
    let joined = out.join("\n");
    assert!(
        joined.contains("create table"),
        "DSL create form shown: {out:?}",
    );
    assert!(
        joined.to_lowercase().matches("create").count() >= 2,
        "more than one create form shown: {out:?}",
    );
}

#[test]
fn help_types_renders_the_type_reference() {
    let out = output_for("help types");
    let joined = out.join("\n").to_lowercase();
    // The type reference names the playground types.
    assert!(
        joined.contains("serial") || joined.contains("shortid"),
        "type reference shown: {out:?}",
    );
}

#[test]
fn help_unknown_topic_points_back_to_the_full_list() {
    let out = output_for("help wibble");
    assert!(
        out.iter()
            .any(|l| l.contains("No help for") && l.contains("wibble")),
        "names the unknown topic: {out:?}",
    );
    assert!(
        out.iter().any(|l| l.contains("Type `help`")),
        "points back at the full list: {out:?}",
    );
}