use std::{collections::HashMap, time::Duration};

use anyhow::Result;
use fancy_duration::FancyDuration;
use human_bytes::human_bytes;
use krata::v1::common::{Guest, GuestMetricFormat, GuestMetricNode, GuestStatus};
use prost_reflect::{DynamicMessage, FieldDescriptor, ReflectMessage, Value as ReflectValue};
use prost_types::Value;
use termtree::Tree;

pub fn proto2dynamic(proto: impl ReflectMessage) -> Result<DynamicMessage> {
    Ok(DynamicMessage::decode(
        proto.descriptor(),
        proto.encode_to_vec().as_slice(),
    )?)
}

pub fn proto2kv(proto: impl ReflectMessage) -> Result<HashMap<String, String>> {
    let message = proto2dynamic(proto)?;
    let mut map = HashMap::new();

    fn crawl(
        prefix: String,
        field: Option<&FieldDescriptor>,
        map: &mut HashMap<String, String>,
        value: &ReflectValue,
    ) {
        match value {
            ReflectValue::Message(child) => {
                for (field, field_value) in child.fields() {
                    let path = if prefix.is_empty() {
                        field.json_name().to_string()
                    } else {
                        format!("{}.{}", prefix, field.json_name())
                    };
                    crawl(path, Some(&field), map, field_value);
                }
            }

            ReflectValue::EnumNumber(number) => {
                if let Some(kind) = field.map(|x| x.kind()) {
                    if let Some(e) = kind.as_enum() {
                        if let Some(value) = e.get_value(*number) {
                            map.insert(prefix, value.name().to_string());
                        }
                    }
                }
            }

            ReflectValue::String(value) => {
                map.insert(prefix.to_string(), value.clone());
            }

            ReflectValue::List(value) => {
                for (x, value) in value.iter().enumerate() {
                    crawl(format!("{}.{}", prefix, x), field, map, value);
                }
            }

            _ => {
                map.insert(prefix.to_string(), value.to_string());
            }
        }
    }

    crawl(
        "".to_string(),
        None,
        &mut map,
        &ReflectValue::Message(message),
    );

    Ok(map)
}

pub fn kv2line(map: HashMap<String, String>) -> String {
    map.iter()
        .map(|(k, v)| format!("{}=\"{}\"", k, v.replace('"', "\\\"")))
        .collect::<Vec<_>>()
        .join(" ")
}

pub fn guest_status_text(status: GuestStatus) -> String {
    match status {
        GuestStatus::Starting => "starting",
        GuestStatus::Started => "started",
        GuestStatus::Destroying => "destroying",
        GuestStatus::Destroyed => "destroyed",
        GuestStatus::Exited => "exited",
        GuestStatus::Failed => "failed",
        _ => "unknown",
    }
    .to_string()
}

pub fn guest_simple_line(guest: &Guest) -> String {
    let state = guest_status_text(
        guest
            .state
            .as_ref()
            .map(|x| x.status())
            .unwrap_or(GuestStatus::Unknown),
    );
    let name = guest.spec.as_ref().map(|x| x.name.as_str()).unwrap_or("");
    let network = guest.state.as_ref().and_then(|x| x.network.as_ref());
    let ipv4 = network.map(|x| x.guest_ipv4.as_str()).unwrap_or("");
    let ipv6 = network.map(|x| x.guest_ipv6.as_str()).unwrap_or("");
    format!("{}\t{}\t{}\t{}\t{}", guest.id, state, name, ipv4, ipv6)
}

fn metrics_value_string(value: Value) -> String {
    proto2dynamic(value)
        .map(|x| serde_json::to_string(&x).ok())
        .ok()
        .flatten()
        .unwrap_or_default()
}

fn metrics_value_numeric(value: Value) -> f64 {
    let string = metrics_value_string(value);
    string.parse::<f64>().ok().unwrap_or(f64::NAN)
}

fn metrics_value_pretty(value: Value, format: GuestMetricFormat) -> String {
    match format {
        GuestMetricFormat::Bytes => human_bytes(metrics_value_numeric(value)),
        GuestMetricFormat::Integer => (metrics_value_numeric(value) as u64).to_string(),
        GuestMetricFormat::DurationSeconds => {
            FancyDuration(Duration::from_secs_f64(metrics_value_numeric(value))).to_string()
        }
        _ => metrics_value_string(value),
    }
}

fn metrics_flat_internal(prefix: &str, node: GuestMetricNode, map: &mut HashMap<String, String>) {
    if let Some(value) = node.value {
        map.insert(prefix.to_string(), metrics_value_string(value));
    }

    for child in node.children {
        let path = if prefix.is_empty() {
            child.name.to_string()
        } else {
            format!("{}.{}", prefix, child.name)
        };
        metrics_flat_internal(&path, child, map);
    }
}

pub fn metrics_flat(root: GuestMetricNode) -> HashMap<String, String> {
    let mut map = HashMap::new();
    metrics_flat_internal("", root, &mut map);
    map
}

pub fn metrics_tree(node: GuestMetricNode) -> Tree<String> {
    let mut name = node.name.to_string();
    let format = node.format();
    if let Some(value) = node.value {
        let value_string = metrics_value_pretty(value, format);
        name.push_str(&format!(": {}", value_string));
    }

    let mut tree = Tree::new(name);
    for child in node.children {
        tree.push(metrics_tree(child));
    }
    tree
}