/// Timeline visualization data structure
use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};

/// Timeline of activities
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Timeline {
    pub entries: Vec<TimelineEntry>,
    pub start: DateTime<Utc>,
    pub end: DateTime<Utc>,
}

impl Timeline {
    pub fn new(start: DateTime<Utc>, end: DateTime<Utc>) -> Self {
        Self {
            entries: Vec::new(),
            start,
            end,
        }
    }

    pub fn add_entry(&mut self, entry: TimelineEntry) {
        self.entries.push(entry);
    }

    pub fn sort_by_time(&mut self) {
        self.entries.sort_by_key(|e| e.timestamp);
    }

    pub fn duration_seconds(&self) -> i64 {
        (self.end - self.start).num_seconds()
    }
}

/// Single timeline entry
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TimelineEntry {
    pub timestamp: DateTime<Utc>,
    pub category: String,
    pub activity: String,
    pub duration_seconds: i64,
    pub color: String, // For visualization
}

impl TimelineEntry {
    pub fn new(
        timestamp: DateTime<Utc>,
        category: String,
        activity: String,
        duration_seconds: i64,
    ) -> Self {
        let color = Self::category_color(&category);
        Self {
            timestamp,
            category,
            activity,
            duration_seconds,
            color,
        }
    }

    fn category_color(category: &str) -> String {
        match category {
            "Development" => "#4CAF50".to_string(), // Green
            "Meeting" => "#2196F3".to_string(),     // Blue
            "Research" => "#FF9800".to_string(),    // Orange
            "Design" => "#9C27B0".to_string(),      // Purple
            _ => "#9E9E9E".to_string(),             // Gray
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_timeline_creation() {
        let start = Utc::now();
        let end = start + chrono::Duration::hours(8);
        let mut timeline = Timeline::new(start, end);

        assert_eq!(timeline.entries.len(), 0);
        assert_eq!(timeline.duration_seconds(), 8 * 3600);

        let entry = TimelineEntry::new(
            start,
            "Development".to_string(),
            "Coding".to_string(),
            3600,
        );
        timeline.add_entry(entry);

        assert_eq!(timeline.entries.len(), 1);
        assert_eq!(timeline.entries[0].color, "#4CAF50");
    }
}