use chrono::{DateTime, Utc};
use heromodels_core::BaseModelData;
use heromodels_derive::model;
use rhai_autobind_macros::rhai_model_export;
use rhai::{CustomType, TypeBuilder};
use serde::{Deserialize, Serialize};

/// Represents the status of an attendee for an event
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum AttendanceStatus {
    Accepted,
    Declined,
    Tentative,
    NoResponse,
}

/// Represents an attendee of an event
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, CustomType)]
pub struct Attendee {
    /// ID of the user attending
    // Assuming user_id might be queryable
    pub contact_id: u32,
    /// Attendance status of the user for the event
    pub status: AttendanceStatus,
}

impl Attendee {
    pub fn new(contact_id: u32) -> Self {
        Self {
            contact_id,
            status: AttendanceStatus::NoResponse,
        }
    }

    pub fn status(mut self, status: AttendanceStatus) -> Self {
        self.status = status;
        self
    }
}

/// Represents an event in a calendar
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, CustomType)]
pub struct Event {
    /// Base model data
    #[serde(flatten)]
    pub base_data: BaseModelData,
    /// Title of the event
    pub title: String,
    /// Optional description of the event
    pub description: Option<String>,
    /// Start time of the event
    pub start_time: DateTime<Utc>,
    /// End time of the event
    pub end_time: DateTime<Utc>,
    /// List of attendees for the event
    pub attendees: Vec<Attendee>,
    /// Optional location of the event
    pub location: Option<String>,
}

impl Event {
    /// Creates a new event
    pub fn new(title: impl ToString, start_time: DateTime<Utc>, end_time: DateTime<Utc>) -> Self {
        Self {
            base_data: BaseModelData::new(),
            title: title.to_string(),
            description: None,
            start_time,
            end_time,
            attendees: Vec::new(),
            location: None,
        }
    }

    /// Sets the title for the event
    pub fn title(mut self, title: impl ToString) -> Self {
        self.title = title.to_string();
        self
    }

    /// Sets the description for the event
    pub fn description(mut self, description: impl ToString) -> Self {
        self.description = Some(description.to_string());
        self
    }

    /// Sets the location for the event
    pub fn location(mut self, location: impl ToString) -> Self {
        self.location = Some(location.to_string());
        self
    }

    /// Adds an attendee to the event
    pub fn add_attendee(mut self, attendee: Attendee) -> Self {
        // Prevent duplicate attendees by contact_id
        if !self.attendees.iter().any(|a| a.contact_id == attendee.contact_id) {
            self.attendees.push(attendee);
        }
        self
    }

    /// Removes an attendee from the event by user_id
    pub fn remove_attendee(mut self, contact_id: u32) -> Self {
        self.attendees.retain(|a| a.contact_id != contact_id);
        self
    }

    /// Updates the status of an existing attendee
    pub fn update_attendee_status(mut self, contact_id: u32, status: AttendanceStatus) -> Self {
        if let Some(attendee) = self.attendees.iter_mut().find(|a| a.contact_id == contact_id) {
            attendee.status = status;
        }
        self
    }

    /// Reschedules the event to new start and end times
    pub fn reschedule(
        mut self,
        new_start_time: DateTime<Utc>,
        new_end_time: DateTime<Utc>,
    ) -> Self {
        // Basic validation: end_time should be after start_time
        if new_end_time > new_start_time {
            self.start_time = new_start_time;
            self.end_time = new_end_time;
        }
        // Optionally, add error handling or return a Result type
        self
    }
}

/// Represents a calendar with events
#[rhai_model_export(
    db_type = "std::sync::Arc<crate::db::hero::OurDB>",
)]
#[model]
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, CustomType)]
pub struct Calendar {
    /// Base model data
    #[serde(flatten)]
    pub base_data: BaseModelData,

    /// Name of the calendar
    pub name: String,

    /// Optional description of the calendar
    pub description: Option<String>,

    /// List of events in the calendar
    // For now, events are embedded. If they become separate models, this would be Vec<[IDType]>.
    pub events: Vec<i64>,
}

impl Calendar {
    /// Creates a new calendar with auto-generated ID
    ///
    /// # Arguments
    /// * `id` - Optional ID for the calendar (use None for auto-generated ID)
    /// * `name` - Name of the calendar
    pub fn new(id: Option<u32>, name: impl ToString) -> Self {
        let mut base_data = BaseModelData::new();
        if let Some(id) = id {
            base_data.update_id(id);
        }

        Self {
            base_data,
            name: name.to_string(),
            description: None,
            events: Vec::new(),
        }
    }

    /// Sets the name for the calendar
    pub fn name(mut self, name: impl ToString) -> Self {
        self.name = name.to_string();
        self
    }

    /// Sets the description for the calendar
    pub fn description(mut self, description: impl ToString) -> Self {
        self.description = Some(description.to_string());
        self
    }

    /// Adds an event to the calendar
    pub fn add_event(mut self, event_id: i64) -> Self {
        // Prevent duplicate events by id
        if !self.events.iter().any(|e_id| *e_id == event_id) {
            self.events.push(event_id);
        }
        self
    }

    /// Removes an event from the calendar by its ID
    pub fn remove_event(mut self, event_id_to_remove: i64) -> Self {
        self.events.retain(|&event_id_in_vec| event_id_in_vec != event_id_to_remove);
        self
    }
}