use std::collections::{HashMap, HashSet};
use std::str::FromStr;

use cvrf_xmlparser::{Severity, CUSA};
use lazy_static::lazy_static;
use rpm_rs::rpm::{get_installed_packages, Package};
use rpm_rs::rpmio::rpmvercmp;
use updateinfo_xmlparser::{RpmInfo, UpdateInfoDb};

use crate::analyzer::db::{CveDb, PackgeDb, SaDb};
use crate::cli::Cli;

lazy_static! {
    pub static ref update_pkgs: PackgeDb = {
        let mut updatedb = UpdateInfoDb::new();
        updatedb.load_xml("test/updateinfo.xml").unwrap();

        let mut pkgdb = PackgeDb::new();
        pkgdb.load_from_updateinfodb(&updatedb);
        pkgdb
    };
    pub static ref sadb: SaDb = {
        let mut _sadb = SaDb::new();

        _sadb.load_from_file("test/cvrf_sainfos.json").unwrap();
        _sadb
    };
    pub static ref cvedb: CveDb = sadb.get_cvedb();
}

pub mod db;

struct Reporter {
    // 已修复的安全更新
    fixed: HashMap<CUSA, HashSet<RpmInfo>>,

    // 可用的安全更新
    avaliable: HashMap<CUSA, HashSet<RpmInfo>>,
}

impl Reporter {
    // 新建一个空的 Reporter
    pub fn new() -> Self {
        let fixed = HashMap::new();
        let avaliable = HashMap::new();

        Self {
            fixed, avaliable
        }
    }

    // get fixed, 不可写
    pub fn get_fixed(&self) -> &HashMap<CUSA, HashSet<RpmInfo>> {
        &self.fixed
    }

    // get avaliable, 只读
    pub fn get_avaliable(&self) -> &HashMap<CUSA, HashSet<RpmInfo>> {
        &self.avaliable
    }

    // 添加包到已修复
    pub fn add_to_fixed(&mut self, cusa: &CUSA, rpm: RpmInfo) {
        // 可以找到则直接 insert
        if let Some(rpms) = self.fixed.get_mut(cusa) {
            rpms.insert(rpm);
        } else {
            let mut rpms = HashSet::new();
            rpms.insert(rpm);
            self.fixed.insert(cusa.clone(), rpms);
        }
    }

    // 添加包到可用更新
    pub fn add_to_avaliable(&mut self, cusa: &CUSA, rpm: RpmInfo) {
        // 可以找到则直接 insert
        if let Some(rpms) = self.avaliable.get_mut(cusa) {
            rpms.insert(rpm);
        } else {
            let mut rpms = HashSet::new();
            rpms.insert(rpm);
            self.avaliable.insert(cusa.clone(), rpms);
        }
    }
}

pub fn cuvat_run(cli: &Cli) -> crate::Result<()> {
    // 只报告 cve 相关
    if cli.cves {
        return list_cves(cli);
    }

    // 只报告 sa 相关
    if cli.sas {
        return list_sas(cli);
    }

    // 生成报告
    if cli.report {
        return repoter(cli);
    }

    // 默认报告格式
    summary(cli)
}

fn list_cves(cli: &Cli) -> crate::Result<()> {
    let reporter = _reporter()?;
    let avaliable = reporter.get_avaliable();
    let severity = Severity::from_str(&cli.severity)?;
    let mut _cves = HashSet::new();
    cli.sources.iter().for_each(|id| { _cves.insert(id); });

    let mut cves = HashSet::new();
    let mut msg = String::new();

    // 仅针对可用更新
    for (cusa, _) in avaliable {
        // 过滤
        if cusa.severity() < &severity {
            continue;
        }

        cusa.cves().iter().for_each(|cve| {
            if let Some(_) = _cves.get(&cve.id) {
                let _ = cves.insert(cve.clone());
                _cves.remove(&cve.id);
            }
        });
    }

    for cve in &cves {
        if cli.info {
            msg = format!("{msg}\n\n{cve:#?}");
        } else {
            msg = format!("{msg}\n{}", cve.id);
        }
    }

    if !_cves.is_empty() {
        msg = format!("{msg}\n\nUnaffected CVEs:\n{_cves:#?}")
    }

    println!("{msg}");

    Ok(())
}

fn list_sas(cli: &Cli) -> crate::Result<()> {
    let reporter = _reporter()?;
    let avaliable = reporter.get_avaliable();
    let severity = Severity::from_str(&cli.severity)?;
    let mut _sas = HashSet::new();
    cli.sources.iter().for_each(|id| { _sas.insert(id); });

    let mut sas = HashSet::new();
    let mut msg = String::new();

    // 仅针对可用更新
    for (cusa, _) in avaliable {
        // 过滤
        if cusa.severity() < &severity {
            continue;
        }

        if let Some(_) = _sas.get(&cusa.id) {
            let _ = sas.insert(cusa.clone());
            _sas.remove(&cusa.id);
        }
    }

    for sa in &sas {
        if cli.info {
            msg = format!("{msg}\n\n{sa:#?}");
        } else {
            msg = format!("{msg}\n{}", sa.id);
        }
    }

    if !_sas.is_empty() {
        msg = format!("{msg}\n\nUnaffected SAs:\n{_sas:#?}")
    }

    println!("{msg}");

    Ok(())
}

// 最为详尽的报告，包括当前系统中软件包所涉及到，已修复和可用但未修复
// 的所有软件包的列表。
fn repoter(cli: &Cli) -> crate::Result<()> {
    let reporter = _reporter()?;
    let fixed = reporter.get_fixed();
    let avaliable = reporter.get_avaliable();
    let _ = fixed;
    let _ = avaliable;
    println!("TODO...");
    Ok(())
}

fn summary(cli: &Cli) -> crate::Result<()> {
    let reporter = _reporter()?;
    let avaliable = reporter.get_avaliable();
    let severity = Severity::from_str(&cli.severity)?;
    let mut total = 0;
    let mut res = vec![0; 5];
    let mut lists = vec![vec![]; 5];
    let mut msg = String::new();

    for (cusa, _) in avaliable {
        // 过滤
        if cusa.severity() < &severity {
            continue;
        }

        let pos: usize = cusa.severity().into();
        total += 1;
        res[pos] += 1;
        lists[pos].push(cusa);
    }

    // 如果需要列出详细的 sa
    if cli.list {
        msg = format!("当前系统未修复的公告列表（共 {total} 个）：\n");
        for sas in &lists {
            for sa in sas {
                msg = format!("{msg}\n{:>4}{}: {:?}", "", sa.id(), sa.severity());
            }
        }
        //msg = format!("{msg}\n\n");
    } else {
        msg = format!(
            "{msg}
本次安全检查共扫描出 {} 个漏洞：

    致命漏洞：{:>3} 个
    高危漏洞：{:>3} 个
    中危漏洞：{:>3} 个
    低危漏洞：{:>3} 个
    ",
            total, res[4], res[3], res[2], res[1]
        );
    }

    println!("{msg}");

    Ok(())
}

fn _reporter() -> crate::Result<Reporter> {
    let mut reporter = Reporter::new();
    // 当前系统所有已安装的 rpm 包
    let installed = get_installed_packages();
    // installed 已被消费掉
    // latest_installed 是所有最新版本软件包的 Vec
    let latest_installed: Vec<Package> = installed
        .into_iter()
        .map(|(_, pkgs)| {
            let mut latest = pkgs[0].clone();
            for pkg in pkgs.into_iter() {
                latest = rpmdb_package_vercmp(latest, pkg);
            }
            latest
        })
        .collect();

    // 获取 sa 更新列表
    for pkg in latest_installed {
        let name = pkg.name();
        if let Some(updates) = update_pkgs.db().get(name) {
            for update in updates {
                // 因 updateinfo 里包含所有架构，故于此做个判断
                // 是否考虑架构信息在不同的版本有所不同？
                if update.arch() != pkg.arch().unwrap() {
                    continue;
                }
                let sainfo = sadb.db().get(update.sa()).unwrap();
                // epoch 判断
                match (update.epoch(), pkg.epoch()) {
                    (Some(_), None) => {
                        reporter.add_to_avaliable(&sainfo, update.clone());
                    }
                    (None, Some(_)) => {
                        reporter.add_to_fixed(&sainfo, update.clone());
                    }
                    _ => {}
                }

                // evr 对比
                if rpmvercmp(&update.evr(), &pkg.evr()) > 0 {
                    reporter.add_to_avaliable(&sainfo, update.clone());
                } else {
                    reporter.add_to_fixed(&sainfo, update.clone());
                }
            }
        }
    }

    Ok(reporter)
}

// 对比两个 rpm Package 的版本，返回最新的一个
fn rpmdb_package_vercmp(pa: Package, pb: Package) -> Package {
    // 首先进行 epoch 的比较
    match (pa.epoch(), pb.epoch()) {
        (Some(_), None) => return pa,
        (None, Some(_)) => return pb,
        _ => {} // 继续往下对比
    }

    if rpmvercmp(&pa.evr(), &pb.evr()) > 0 {
        return pa;
    } else {
        return pb;
    }
}