use cm_dashboard_shared::{Metric, MetricValue, Status};
use ratatui::{
    layout::Rect,
    text::{Line, Span, Text},
    widgets::Paragraph,
    Frame,
};

use super::Widget;
use crate::ui::theme::{StatusIcons, Typography};

/// System widget displaying NixOS info, CPU, RAM, and Storage in unified layout
#[derive(Clone)]
pub struct SystemWidget {
    // NixOS information
    nixos_build: Option<String>,
    config_hash: Option<String>,
    active_users: Option<String>,
    agent_hash: Option<String>,
    
    // CPU metrics
    cpu_load_1min: Option<f32>,
    cpu_load_5min: Option<f32>,
    cpu_load_15min: Option<f32>,
    cpu_frequency: Option<f32>,
    cpu_status: Status,
    
    // Memory metrics
    memory_usage_percent: Option<f32>,
    memory_used_gb: Option<f32>,
    memory_total_gb: Option<f32>,
    tmp_usage_percent: Option<f32>,
    tmp_used_gb: Option<f32>,
    tmp_total_gb: Option<f32>,
    memory_status: Status,
    
    // Storage metrics (collected from disk metrics)
    storage_pools: Vec<StoragePool>,
    
    // Overall status
    has_data: bool,
}

#[derive(Clone)]
struct StoragePool {
    name: String,
    mount_point: String,
    pool_type: String, // "Single", "Raid0", etc.
    drives: Vec<StorageDrive>,
    usage_percent: Option<f32>,
    used_gb: Option<f32>,
    total_gb: Option<f32>,
    status: Status,
}

#[derive(Clone)]
struct StorageDrive {
    name: String,
    temperature: Option<f32>,
    wear_percent: Option<f32>,
    status: Status,
}

impl SystemWidget {
    pub fn new() -> Self {
        Self {
            nixos_build: None,
            config_hash: None,
            active_users: None,
            agent_hash: None,
            cpu_load_1min: None,
            cpu_load_5min: None,
            cpu_load_15min: None,
            cpu_frequency: None,
            cpu_status: Status::Unknown,
            memory_usage_percent: None,
            memory_used_gb: None,
            memory_total_gb: None,
            tmp_usage_percent: None,
            tmp_used_gb: None,
            tmp_total_gb: None,
            memory_status: Status::Unknown,
            storage_pools: Vec::new(),
            has_data: false,
        }
    }

    /// Format CPU load averages
    fn format_cpu_load(&self) -> String {
        match (self.cpu_load_1min, self.cpu_load_5min, self.cpu_load_15min) {
            (Some(l1), Some(l5), Some(l15)) => {
                format!("{:.2} {:.2} {:.2}", l1, l5, l15)
            }
            _ => "— — —".to_string(),
        }
    }

    /// Format CPU frequency
    fn format_cpu_frequency(&self) -> String {
        match self.cpu_frequency {
            Some(freq) => format!("{:.0} MHz", freq),
            None => "— MHz".to_string(),
        }
    }

    /// Format memory usage
    fn format_memory_usage(&self) -> String {
        match (self.memory_usage_percent, self.memory_used_gb, self.memory_total_gb) {
            (Some(pct), Some(used), Some(total)) => {
                format!("{:.0}% {:.1}GB/{:.1}GB", pct, used, total)
            }
            _ => "—% —GB/—GB".to_string(),
        }
    }

    /// Format /tmp usage
    fn format_tmp_usage(&self) -> String {
        match (self.tmp_usage_percent, self.tmp_used_gb, self.tmp_total_gb) {
            (Some(pct), Some(used), Some(total)) => {
                let used_str = if used < 0.1 {
                    format!("{:.0}B", used * 1024.0) // Show as MB if very small
                } else {
                    format!("{:.1}GB", used)
                };
                format!("{:.0}% {}/{:.1}GB", pct, used_str, total)
            }
            _ => "—% —GB/—GB".to_string(),
        }
    }

    /// Get the current agent hash for rebuild completion detection
    pub fn get_agent_hash(&self) -> Option<&String> {
        self.agent_hash.as_ref()
    }

    /// Get mount point for a pool name
    fn get_mount_point_for_pool(&self, pool_name: &str) -> String {
        match pool_name {
            "root" => "/".to_string(),
            "steampool" => "/mnt/steampool".to_string(),
            "steampool_1" => "/steampool_1".to_string(),
            "steampool_2" => "/steampool_2".to_string(),
            _ => format!("/{}", pool_name), // Default fallback
        }
    }

    /// Parse storage metrics into pools and drives
    fn update_storage_from_metrics(&mut self, metrics: &[&Metric]) {
        let mut pools: std::collections::HashMap<String, StoragePool> = std::collections::HashMap::new();
        
        for metric in metrics {
            if metric.name.starts_with("disk_") {
                if let Some(pool_name) = self.extract_pool_name(&metric.name) {
                    let mount_point = self.get_mount_point_for_pool(&pool_name);
                    let pool = pools.entry(pool_name.clone()).or_insert_with(|| StoragePool {
                        name: pool_name.clone(),
                        mount_point: mount_point.clone(),
                        pool_type: "Single".to_string(), // Default, could be enhanced
                        drives: Vec::new(),
                        usage_percent: None,
                        used_gb: None,
                        total_gb: None,
                        status: Status::Unknown,
                    });

                    // Parse different metric types
                    if metric.name.contains("_usage_percent") {
                        if let MetricValue::Float(usage) = metric.value {
                            pool.usage_percent = Some(usage);
                            pool.status = metric.status.clone();
                        }
                    } else if metric.name.contains("_used_gb") {
                        if let MetricValue::Float(used) = metric.value {
                            pool.used_gb = Some(used);
                        }
                    } else if metric.name.contains("_total_gb") {
                        if let MetricValue::Float(total) = metric.value {
                            pool.total_gb = Some(total);
                        }
                    } else if metric.name.contains("_temperature") {
                        if let Some(drive_name) = self.extract_drive_name(&metric.name) {
                            // Find existing drive or create new one
                            let drive_exists = pool.drives.iter().any(|d| d.name == drive_name);
                            if !drive_exists {
                                pool.drives.push(StorageDrive {
                                    name: drive_name.clone(),
                                    temperature: None,
                                    wear_percent: None,
                                    status: Status::Unknown,
                                });
                            }
                            
                            if let Some(drive) = pool.drives.iter_mut().find(|d| d.name == drive_name) {
                                if let MetricValue::Float(temp) = metric.value {
                                    drive.temperature = Some(temp);
                                    drive.status = metric.status.clone();
                                }
                            }
                        }
                    } else if metric.name.contains("_wear_percent") {
                        if let Some(drive_name) = self.extract_drive_name(&metric.name) {
                            // Find existing drive or create new one
                            let drive_exists = pool.drives.iter().any(|d| d.name == drive_name);
                            if !drive_exists {
                                pool.drives.push(StorageDrive {
                                    name: drive_name.clone(),
                                    temperature: None,
                                    wear_percent: None,
                                    status: Status::Unknown,
                                });
                            }
                            
                            if let Some(drive) = pool.drives.iter_mut().find(|d| d.name == drive_name) {
                                if let MetricValue::Float(wear) = metric.value {
                                    drive.wear_percent = Some(wear);
                                    drive.status = metric.status.clone();
                                }
                            }
                        }
                    }
                }
            }
        }

        // Convert to sorted vec for consistent ordering
        let mut pool_list: Vec<StoragePool> = pools.into_values().collect();
        pool_list.sort_by(|a, b| a.name.cmp(&b.name)); // Sort alphabetically by name
        self.storage_pools = pool_list;
    }

    /// Extract pool name from disk metric name
    fn extract_pool_name(&self, metric_name: &str) -> Option<String> {
        if let Some(captures) = metric_name.strip_prefix("disk_") {
            if let Some(pos) = captures.find('_') {
                return Some(captures[..pos].to_string());
            }
        }
        None
    }

    /// Extract drive name from disk metric name  
    fn extract_drive_name(&self, metric_name: &str) -> Option<String> {
        // Pattern: disk_pool_drive_metric
        let parts: Vec<&str> = metric_name.split('_').collect();
        if parts.len() >= 3 && parts[0] == "disk" {
            return Some(parts[2].to_string());
        }
        None
    }

    /// Render storage section with tree structure
    fn render_storage(&self) -> Vec<Line<'_>> {
        let mut lines = Vec::new();

        for pool in &self.storage_pools {
            // Pool header line
            let usage_text = match (pool.usage_percent, pool.used_gb, pool.total_gb) {
                (Some(pct), Some(used), Some(total)) => {
                    format!("{:.0}% {:.1}GB/{:.1}GB", pct, used, total)
                }
                _ => "—% —GB/—GB".to_string(),
            };
            
            let pool_label = if pool.pool_type.to_lowercase() == "single" {
                format!("{}:", pool.mount_point)
            } else {
                format!("{} ({}):", pool.mount_point, pool.pool_type)
            };
            let pool_spans = StatusIcons::create_status_spans(
                pool.status.clone(),
                &pool_label
            );
            lines.push(Line::from(pool_spans));

            // Drive lines with tree structure
            let has_usage_line = pool.usage_percent.is_some();
            for (i, drive) in pool.drives.iter().enumerate() {
                let is_last_drive = i == pool.drives.len() - 1;
                let tree_symbol = if is_last_drive && !has_usage_line { "└─" } else { "├─" };
                
                let mut drive_info = Vec::new();
                if let Some(temp) = drive.temperature {
                    drive_info.push(format!("T: {:.0}C", temp));
                }
                if let Some(wear) = drive.wear_percent {
                    drive_info.push(format!("W: {:.0}%", wear));
                }
                let drive_text = if drive_info.is_empty() {
                    drive.name.clone()
                } else {
                    format!("{} {}", drive.name, drive_info.join(" • "))
                };

                let mut drive_spans = vec![
                    Span::raw("  "),
                    Span::styled(tree_symbol, Typography::tree()),
                    Span::raw(" "),
                ];
                drive_spans.extend(StatusIcons::create_status_spans(drive.status.clone(), &drive_text));
                lines.push(Line::from(drive_spans));
            }

            // Usage line
            if pool.usage_percent.is_some() {
                let tree_symbol = "└─";
                let mut usage_spans = vec![
                    Span::raw("  "),
                    Span::styled(tree_symbol, Typography::tree()),
                    Span::raw(" "),
                ];
                usage_spans.extend(StatusIcons::create_status_spans(pool.status.clone(), &usage_text));
                lines.push(Line::from(usage_spans));
            }
        }

        lines
    }
}

impl Widget for SystemWidget {
    fn update_from_metrics(&mut self, metrics: &[&Metric]) {
        self.has_data = !metrics.is_empty();

        for metric in metrics {
            match metric.name.as_str() {
                // NixOS metrics
                "system_nixos_build" => {
                    if let MetricValue::String(build) = &metric.value {
                        self.nixos_build = Some(build.clone());
                    }
                }
                "system_config_hash" => {
                    if let MetricValue::String(hash) = &metric.value {
                        self.config_hash = Some(hash.clone());
                    }
                }
                "system_active_users" => {
                    if let MetricValue::String(users) = &metric.value {
                        self.active_users = Some(users.clone());
                    }
                }
                "agent_version" => {
                    if let MetricValue::String(version) = &metric.value {
                        self.agent_hash = Some(version.clone());
                    }
                }
                
                // CPU metrics
                "cpu_load_1min" => {
                    if let MetricValue::Float(load) = metric.value {
                        self.cpu_load_1min = Some(load);
                        self.cpu_status = metric.status.clone();
                    }
                }
                "cpu_load_5min" => {
                    if let MetricValue::Float(load) = metric.value {
                        self.cpu_load_5min = Some(load);
                    }
                }
                "cpu_load_15min" => {
                    if let MetricValue::Float(load) = metric.value {
                        self.cpu_load_15min = Some(load);
                    }
                }
                "cpu_frequency_mhz" => {
                    if let MetricValue::Float(freq) = metric.value {
                        self.cpu_frequency = Some(freq);
                    }
                }
                
                // Memory metrics
                "memory_usage_percent" => {
                    if let MetricValue::Float(usage) = metric.value {
                        self.memory_usage_percent = Some(usage);
                        self.memory_status = metric.status.clone();
                    }
                }
                "memory_used_gb" => {
                    if let MetricValue::Float(used) = metric.value {
                        self.memory_used_gb = Some(used);
                    }
                }
                "memory_total_gb" => {
                    if let MetricValue::Float(total) = metric.value {
                        self.memory_total_gb = Some(total);
                    }
                }
                
                // Tmpfs metrics
                "memory_tmp_usage_percent" => {
                    if let MetricValue::Float(usage) = metric.value {
                        self.tmp_usage_percent = Some(usage);
                    }
                }
                "memory_tmp_used_gb" => {
                    if let MetricValue::Float(used) = metric.value {
                        self.tmp_used_gb = Some(used);
                    }
                }
                "memory_tmp_total_gb" => {
                    if let MetricValue::Float(total) = metric.value {
                        self.tmp_total_gb = Some(total);
                    }
                }
                _ => {}
            }
        }

        // Update storage from all disk metrics
        self.update_storage_from_metrics(metrics);
    }

}

impl SystemWidget {
    /// Render with scroll offset support
    pub fn render_with_scroll(&mut self, frame: &mut Frame, area: Rect, scroll_offset: usize) {
        let mut lines = Vec::new();

        // NixOS section
        lines.push(Line::from(vec![
            Span::styled("NixOS:", Typography::widget_title())
        ]));
        
        let config_text = self.config_hash.as_deref().unwrap_or("unknown");
        lines.push(Line::from(vec![
            Span::styled(format!("Build: {}", config_text), Typography::secondary())
        ]));
        
        let agent_hash_text = self.agent_hash.as_deref().unwrap_or("unknown");
        let short_hash = if agent_hash_text.len() > 8 && agent_hash_text != "unknown" {
            &agent_hash_text[..8]
        } else {
            agent_hash_text
        };
        lines.push(Line::from(vec![
            Span::styled(format!("Agent: {}", short_hash), Typography::secondary())
        ]));

        // CPU section
        lines.push(Line::from(vec![
            Span::styled("CPU:", Typography::widget_title())
        ]));
        
        let load_text = self.format_cpu_load();
        let cpu_spans = StatusIcons::create_status_spans(
            self.cpu_status.clone(),
            &format!("Load: {}", load_text)
        );
        lines.push(Line::from(cpu_spans));
        
        let freq_text = self.format_cpu_frequency();
        lines.push(Line::from(vec![
            Span::styled("  └─ ", Typography::tree()),
            Span::styled(format!("Freq: {}", freq_text), Typography::secondary())
        ]));

        // RAM section
        lines.push(Line::from(vec![
            Span::styled("RAM:", Typography::widget_title())
        ]));
        
        let memory_text = self.format_memory_usage();
        let memory_spans = StatusIcons::create_status_spans(
            self.memory_status.clone(),
            &format!("Usage: {}", memory_text)
        );
        lines.push(Line::from(memory_spans));

        let tmp_text = self.format_tmp_usage();
        let mut tmp_spans = vec![
            Span::styled("  └─ ", Typography::tree()),
        ];
        tmp_spans.extend(StatusIcons::create_status_spans(
            self.memory_status.clone(),
            &format!("/tmp: {}", tmp_text)
        ));
        lines.push(Line::from(tmp_spans));

        // Storage section
        lines.push(Line::from(vec![
            Span::styled("Storage:", Typography::widget_title())
        ]));
        
        // Storage items with overflow handling
        let storage_lines = self.render_storage();
        let remaining_space = area.height.saturating_sub(lines.len() as u16);
        
        if storage_lines.len() <= remaining_space as usize {
            // All storage lines fit
            lines.extend(storage_lines);
        } else if remaining_space >= 2 {
            // Show what we can and add overflow indicator
            let lines_to_show = (remaining_space - 1) as usize; // Reserve 1 line for overflow
            lines.extend(storage_lines.iter().take(lines_to_show).cloned());
            
            // Count hidden pools
            let mut hidden_pools = 0;
            let mut current_pool = String::new();
            for (i, line) in storage_lines.iter().enumerate() {
                if i >= lines_to_show {
                    // Check if this line represents a new pool (no indentation)
                    if let Some(first_span) = line.spans.first() {
                        let text = first_span.content.as_ref();
                        if !text.starts_with("  ") && text.contains(':') {
                            let pool_name = text.split(':').next().unwrap_or("").trim();
                            if pool_name != current_pool {
                                hidden_pools += 1;
                                current_pool = pool_name.to_string();
                            }
                        }
                    }
                }
            }
            
            if hidden_pools > 0 {
                let overflow_text = format!(
                    "... and {} more pool{}",
                    hidden_pools,
                    if hidden_pools == 1 { "" } else { "s" }
                );
                lines.push(Line::from(vec![
                    Span::styled(overflow_text, Typography::muted())
                ]));
            }
        }

        // Apply scroll offset
        let total_lines = lines.len();
        let available_height = area.height as usize;
        
        // Always apply scrolling if scroll_offset > 0, even if content fits
        if scroll_offset > 0 || total_lines > available_height {
            let max_scroll = if total_lines > available_height {
                total_lines - available_height
            } else {
                total_lines.saturating_sub(1)
            };
            let effective_scroll = scroll_offset.min(max_scroll);
            
            // Take only the visible portion after scrolling
            let visible_lines: Vec<Line> = lines
                .into_iter()
                .skip(effective_scroll)
                .take(available_height)
                .collect();
                
            let paragraph = Paragraph::new(Text::from(visible_lines));
            frame.render_widget(paragraph, area);
        } else {
            // All content fits and no scroll offset, render normally
            let paragraph = Paragraph::new(Text::from(lines));
            frame.render_widget(paragraph, area);
        }
    }
}