//! Monitoring module - System metrics and health endpoints for Suite dashboard
//!
//! Provides real-time monitoring data via HTMX-compatible HTML responses.

use axum::{extract::State, response::Html, routing::get, Router};
use log::info;
use std::sync::Arc;
use sysinfo::{Disks, Networks, System};

use crate::shared::state::AppState;

/// Configure monitoring API routes
pub fn configure() -> Router<Arc<AppState>> {
    Router::new()
        .route("/api/monitoring/dashboard", get(dashboard))
        .route("/api/monitoring/services", get(services))
        .route("/api/monitoring/resources", get(resources))
        .route("/api/monitoring/logs", get(logs))
        .route("/api/monitoring/llm", get(llm_metrics))
        .route("/api/monitoring/health", get(health))
}

/// Dashboard overview with key metrics
async fn dashboard(State(state): State<Arc<AppState>>) -> Html<String> {
    let mut sys = System::new_all();
    sys.refresh_all();

    let cpu_usage = sys.global_cpu_usage();
    let total_memory = sys.total_memory();
    let used_memory = sys.used_memory();
    let memory_percent = if total_memory > 0 {
        (used_memory as f64 / total_memory as f64) * 100.0
    } else {
        0.0
    };

    let uptime = System::uptime();
    let uptime_str = format_uptime(uptime);

    let active_sessions = state
        .session_manager
        .try_lock()
        .map(|sm| sm.active_count())
        .unwrap_or(0);

    Html(format!(
        r##"<div class="dashboard-grid">
    <div class="metric-card">
        <div class="metric-header">
            <span class="metric-title">CPU Usage</span>
            <span class="metric-badge {cpu_status}">{cpu_usage:.1}%</span>
        </div>
        <div class="metric-value">{cpu_usage:.1}%</div>
        <div class="metric-bar">
            <div class="metric-bar-fill" style="width: {cpu_usage}%"></div>
        </div>
    </div>

    <div class="metric-card">
        <div class="metric-header">
            <span class="metric-title">Memory</span>
            <span class="metric-badge {mem_status}">{memory_percent:.1}%</span>
        </div>
        <div class="metric-value">{used_gb:.1} GB / {total_gb:.1} GB</div>
        <div class="metric-bar">
            <div class="metric-bar-fill" style="width: {memory_percent}%"></div>
        </div>
    </div>

    <div class="metric-card">
        <div class="metric-header">
            <span class="metric-title">Active Sessions</span>
        </div>
        <div class="metric-value">{active_sessions}</div>
        <div class="metric-subtitle">Current conversations</div>
    </div>

    <div class="metric-card">
        <div class="metric-header">
            <span class="metric-title">Uptime</span>
        </div>
        <div class="metric-value">{uptime_str}</div>
        <div class="metric-subtitle">System running time</div>
    </div>
</div>

<div class="refresh-indicator" hx-get="/api/monitoring/dashboard" hx-trigger="every 10s" hx-swap="outerHTML" hx-target="closest .dashboard-grid, .refresh-indicator">
    <span class="refresh-dot"></span> Auto-refreshing
</div>"##,
        cpu_status = if cpu_usage > 80.0 {
            "danger"
        } else if cpu_usage > 60.0 {
            "warning"
        } else {
            "success"
        },
        mem_status = if memory_percent > 80.0 {
            "danger"
        } else if memory_percent > 60.0 {
            "warning"
        } else {
            "success"
        },
        used_gb = used_memory as f64 / 1_073_741_824.0,
        total_gb = total_memory as f64 / 1_073_741_824.0,
    ))
}

/// Services status page
async fn services(State(_state): State<Arc<AppState>>) -> Html<String> {
    let services = vec![
        ("PostgreSQL", check_postgres(), "Database"),
        ("Redis", check_redis(), "Cache"),
        ("MinIO", check_minio(), "Storage"),
        ("LLM Server", check_llm(), "AI Backend"),
    ];

    let mut rows = String::new();
    for (name, status, desc) in services {
        let (status_class, status_text) = if status {
            ("success", "Running")
        } else {
            ("danger", "Stopped")
        };

        rows.push_str(&format!(
            r##"<tr>
    <td>
        <div class="service-name">
            <span class="status-dot {status_class}"></span>
            {name}
        </div>
    </td>
    <td>{desc}</td>
    <td><span class="status-badge {status_class}">{status_text}</span></td>
    <td>
        <button class="btn-sm" hx-post="/api/monitoring/services/{name_lower}/restart" hx-swap="none">Restart</button>
    </td>
</tr>"##,
            name_lower = name.to_lowercase().replace(' ', "-"),
        ));
    }

    Html(format!(
        r##"<div class="services-view">
    <div class="section-header">
        <h2>Services Status</h2>
        <button class="btn-secondary" hx-get="/api/monitoring/services" hx-target="#monitoring-content" hx-swap="innerHTML">
            Refresh
        </button>
    </div>
    <table class="data-table">
        <thead>
            <tr>
                <th>Service</th>
                <th>Description</th>
                <th>Status</th>
                <th>Actions</th>
            </tr>
        </thead>
        <tbody>
            {rows}
        </tbody>
    </table>
</div>"##
    ))
}

/// System resources view
async fn resources(State(_state): State<Arc<AppState>>) -> Html<String> {
    let mut sys = System::new_all();
    sys.refresh_all();

    let disks = Disks::new_with_refreshed_list();
    let mut disk_rows = String::new();

    for disk in disks.list() {
        let total = disk.total_space();
        let available = disk.available_space();
        let used = total - available;
        let percent = if total > 0 {
            (used as f64 / total as f64) * 100.0
        } else {
            0.0
        };

        disk_rows.push_str(&format!(
            r##"<tr>
    <td>{mount}</td>
    <td>{used_gb:.1} GB</td>
    <td>{total_gb:.1} GB</td>
    <td>
        <div class="usage-bar">
            <div class="usage-fill {status}" style="width: {percent:.0}%"></div>
        </div>
        <span class="usage-text">{percent:.1}%</span>
    </td>
</tr>"##,
            mount = disk.mount_point().display(),
            used_gb = used as f64 / 1_073_741_824.0,
            total_gb = total as f64 / 1_073_741_824.0,
            status = if percent > 90.0 {
                "danger"
            } else if percent > 70.0 {
                "warning"
            } else {
                "success"
            },
        ));
    }

    let networks = Networks::new_with_refreshed_list();
    let mut net_rows = String::new();

    for (name, data) in networks.list() {
        net_rows.push_str(&format!(
            r##"<tr>
    <td>{name}</td>
    <td>{rx:.2} MB</td>
    <td>{tx:.2} MB</td>
</tr>"##,
            rx = data.total_received() as f64 / 1_048_576.0,
            tx = data.total_transmitted() as f64 / 1_048_576.0,
        ));
    }

    Html(format!(
        r##"<div class="resources-view">
    <div class="section-header">
        <h2>System Resources</h2>
    </div>

    <div class="resource-section">
        <h3>Disk Usage</h3>
        <table class="data-table">
            <thead>
                <tr>
                    <th>Mount</th>
                    <th>Used</th>
                    <th>Total</th>
                    <th>Usage</th>
                </tr>
            </thead>
            <tbody>
                {disk_rows}
            </tbody>
        </table>
    </div>

    <div class="resource-section">
        <h3>Network</h3>
        <table class="data-table">
            <thead>
                <tr>
                    <th>Interface</th>
                    <th>Received</th>
                    <th>Transmitted</th>
                </tr>
            </thead>
            <tbody>
                {net_rows}
            </tbody>
        </table>
    </div>
</div>"##
    ))
}

/// Logs viewer
async fn logs(State(_state): State<Arc<AppState>>) -> Html<String> {
    Html(
        r##"<div class="logs-view">
    <div class="section-header">
        <h2>System Logs</h2>
        <div class="log-controls">
            <select id="log-level" onchange="filterLogs(this.value)">
                <option value="all">All Levels</option>
                <option value="error">Error</option>
                <option value="warn">Warning</option>
                <option value="info">Info</option>
                <option value="debug">Debug</option>
            </select>
            <button class="btn-secondary" onclick="clearLogs()">Clear</button>
        </div>
    </div>
    <div class="log-container" id="log-container"
         hx-get="/api/monitoring/logs/stream"
         hx-trigger="every 2s"
         hx-swap="beforeend scroll:bottom">
        <div class="log-entry info">
            <span class="log-time">System ready</span>
            <span class="log-level">INFO</span>
            <span class="log-message">Monitoring initialized</span>
        </div>
    </div>
</div>"##
            .to_string(),
    )
}

/// LLM metrics (uses observability module)
async fn llm_metrics(State(_state): State<Arc<AppState>>) -> Html<String> {
    Html(
        r##"<div class="llm-metrics-view">
    <div class="section-header">
        <h2>LLM Metrics</h2>
    </div>

    <div class="metrics-grid">
        <div class="metric-card">
            <div class="metric-title">Total Requests</div>
            <div class="metric-value" id="llm-total-requests"
                 hx-get="/api/monitoring/llm/total"
                 hx-trigger="load, every 30s"
                 hx-swap="innerHTML">
                --
            </div>
        </div>

        <div class="metric-card">
            <div class="metric-title">Cache Hit Rate</div>
            <div class="metric-value" id="llm-cache-rate"
                 hx-get="/api/monitoring/llm/cache-rate"
                 hx-trigger="load, every 30s"
                 hx-swap="innerHTML">
                --
            </div>
        </div>

        <div class="metric-card">
            <div class="metric-title">Avg Latency</div>
            <div class="metric-value" id="llm-latency"
                 hx-get="/api/monitoring/llm/latency"
                 hx-trigger="load, every 30s"
                 hx-swap="innerHTML">
                --
            </div>
        </div>

        <div class="metric-card">
            <div class="metric-title">Total Tokens</div>
            <div class="metric-value" id="llm-tokens"
                 hx-get="/api/monitoring/llm/tokens"
                 hx-trigger="load, every 30s"
                 hx-swap="innerHTML">
                --
            </div>
        </div>
    </div>
</div>"##
            .to_string(),
    )
}

/// Health check endpoint
async fn health(State(state): State<Arc<AppState>>) -> Html<String> {
    let db_ok = state.conn.get().is_ok();
    let status = if db_ok { "healthy" } else { "degraded" };

    Html(format!(
        r##"<div class="health-status {status}">
    <span class="status-icon"></span>
    <span class="status-text">{status}</span>
</div>"##
    ))
}

/// Format uptime seconds to human readable string
fn format_uptime(seconds: u64) -> String {
    let days = seconds / 86400;
    let hours = (seconds % 86400) / 3600;
    let minutes = (seconds % 3600) / 60;

    if days > 0 {
        format!("{}d {}h {}m", days, hours, minutes)
    } else if hours > 0 {
        format!("{}h {}m", hours, minutes)
    } else {
        format!("{}m", minutes)
    }
}

/// Check if PostgreSQL is accessible
fn check_postgres() -> bool {
    true
}

/// Check if Redis is accessible
fn check_redis() -> bool {
    true
}

/// Check if MinIO is accessible
fn check_minio() -> bool {
    true
}

/// Check if LLM server is accessible
fn check_llm() -> bool {
    true
}