// src/state/pages/auth.rs
use crate::state::canvas_state::CanvasState;

#[derive(Default)]
pub struct AuthState {
    pub return_selected: bool,
    pub username: String,
    pub password: String,
    pub error_message: Option<String>,
    pub current_field: usize,
    pub current_cursor_pos: usize,
    pub auth_token: Option<String>,
    pub user_id: Option<String>,
    pub role: Option<String>,
    pub has_unsaved_changes: bool,
}

impl AuthState {
    pub fn new() -> Self {
        Self {
            return_selected: false,
            username: String::new(),
            password: String::new(),
            error_message: None,
            current_field: 0,
            current_cursor_pos: 0,
            auth_token: None,
            user_id: None,
            role: None,
            has_unsaved_changes: false,
        }
    }
}

impl CanvasState for AuthState {
    fn current_field(&self) -> usize {
        self.current_field
    }

    fn current_cursor_pos(&self) -> usize {
        let len = match self.current_field {
            0 => self.username.len(),
            1 => self.password.len(),
            _ => 0,
        };
        self.current_cursor_pos.min(len)
    }

    fn has_unsaved_changes(&self) -> bool {
        self.has_unsaved_changes
    }

    fn inputs(&self) -> Vec<&String> {
        vec![&self.username, &self.password]
    }

    fn get_current_input(&self) -> &str {
        match self.current_field {
            0 => &self.username,
            1 => &self.password,
            _ => "",
        }
    }

    fn get_current_input_mut(&mut self) -> &mut String {
        match self.current_field {
            0 => &mut self.username,
            1 => &mut self.password,
            _ => panic!("Invalid current_field index in AuthState"),
        }
    }

    fn fields(&self) -> Vec<&str> {
        vec!["Username/Email", "Password"]
    }

    fn set_current_field(&mut self, index: usize) {
        if index < 2 { // AuthState only has 2 fields
            self.current_field = index;
            // IMPORTANT: Clamp cursor position to the length of the NEW field
            let len = match self.current_field {
               0 => self.username.len(),
               1 => self.password.len(),
               _ => 0,
            };
            self.current_cursor_pos = self.current_cursor_pos.min(len);
        }
    }

    fn set_current_cursor_pos(&mut self, pos: usize) {
        let len = match self.current_field {
           0 => self.username.len(),
           1 => self.password.len(),
           _ => 0,
        };
        // Ensure stored position is always valid
        self.current_cursor_pos = pos.min(len);
    }

    fn set_has_unsaved_changes(&mut self, changed: bool) {
        // Allow the generic handler to signal changes
        self.has_unsaved_changes = changed;
    }
}