//! Saved view types and DTOs.
//!
//! Saved views are user-defined filter/sort configurations that can be pinned
//! to the sidebar for quick access. Each view targets a specific domain
//! (tasks, emails, or events) and stores its filter criteria as JSON.

use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use strum_macros::EnumString;
use crate::id_types::{SavedViewId, UserId, ProjectId};

use super::shared::{DbValue, ParseableEnum, SortDirection};

// ============ Saved Views ============

/// Type of view for saved filters.
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Default, EnumString)]
#[serde(rename_all = "lowercase")]
pub enum ViewType {
    /// Task list view.
    #[default]
    #[strum(serialize = "tasks")]
    Tasks,
    /// Email list view.
    #[strum(serialize = "emails")]
    Emails,
    /// Event list view.
    #[strum(serialize = "events")]
    Events,
}

impl ViewType {
    /// Returns a human-readable display string.
    pub fn as_str(&self) -> &'static str {
        match self {
            ViewType::Tasks => "Tasks",
            ViewType::Emails => "Emails",
            ViewType::Events => "Events",
        }
    }

}

impl ParseableEnum for ViewType {}

impl DbValue for ViewType {
    fn db_value(&self) -> &'static str {
        match self {
            ViewType::Tasks => "tasks",
            ViewType::Emails => "emails",
            ViewType::Events => "events",
        }
    }
}

/// Column to sort saved view results by.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum SortField {
    /// Sort by calculated urgency score (tasks only).
    Urgency,
    /// Sort by due date (tasks) or received date (emails). Nulls sort last.
    Due,
    /// Sort by creation timestamp.
    CreatedAt,
    /// Sort alphabetically by description (tasks) or subject (emails) or title (events).
    Description,
    /// Sort by priority level (High > Medium > Low, tasks only).
    Priority,
    /// Sort alphabetically by associated project name. Nulls sort last.
    Project,
}

/// Filter criteria stored as JSON.
#[derive(Debug, Clone, Serialize, Deserialize, Default)]
#[serde(rename_all = "camelCase")]
pub struct ViewFilters {
    /// Filter by status.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub status: Option<Vec<crate::models::TaskStatus>>,
    /// Filter by project ID.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub project_id: Option<ProjectId>,
    /// Filter by tags (all must match).
    #[serde(skip_serializing_if = "Option::is_none")]
    pub tags: Option<Vec<String>>,
    /// Filter by priority.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub priority: Option<Vec<crate::models::Priority>>,
    /// Filter by due date range start.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub due_from: Option<DateTime<Utc>>,
    /// Filter by due date range end.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub due_to: Option<DateTime<Utc>>,
    /// Filter by read/unread status (emails only).
    #[serde(skip_serializing_if = "Option::is_none")]
    pub is_read: Option<bool>,
    /// Filter by archived status.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub is_archived: Option<bool>,
    /// Show only snoozed items.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub is_snoozed: Option<bool>,
    /// Show only items waiting for response.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub is_waiting: Option<bool>,
}

/// A saved view / filter configuration.
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct SavedView {
    /// Unique view ID.
    pub id: SavedViewId,
    /// User who owns this view.
    #[serde(skip_serializing)]
    pub user_id: UserId,
    /// Display name for the view.
    pub name: String,
    /// Type of view (tasks, emails, events).
    pub view_type: ViewType,
    /// Filter criteria.
    pub filters: ViewFilters,
    /// Sort field.
    pub sort_by: Option<SortField>,
    /// Sort order.
    pub sort_order: SortDirection,
    /// Whether to show in sidebar.
    pub is_pinned: bool,
    /// Position in sidebar.
    pub position: i32,
    /// When the view was created.
    pub created_at: DateTime<Utc>,
    /// When the view was last modified.
    pub updated_at: DateTime<Utc>,
}

// ============ Saved View DTOs ============

/// Data for creating a new saved view.
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct NewSavedView {
    /// Display name for the view.
    pub name: String,
    /// Type of view (tasks, emails, events).
    pub view_type: ViewType,
    /// Filter criteria.
    pub filters: ViewFilters,
    /// Sort field.
    pub sort_by: Option<SortField>,
    /// Sort order.
    pub sort_order: Option<SortDirection>,
    /// Whether to pin to sidebar.
    pub is_pinned: Option<bool>,
}