use crate::{
    config::{Config, IClashTemp, IProfiles, IVerge},
    constants,
    core::handle,
    logging,
    process::AsyncHandler,
    utils::{
        dirs::{self, PathBufExec as _},
        help,
    },
};
use anyhow::Result;
use chrono::{Local, TimeZone as _};
use clash_verge_logging::Type;
#[cfg(any(target_os = "macos", target_os = "windows"))]
use std::path::Path;
use std::{path::PathBuf, str::FromStr as _};
use tauri_plugin_shell::ShellExt as _;
use tokio::fs;
use tokio::fs::DirEntry;

#[cfg(target_os = "windows")]
async fn delete_snapshot_logs(log_dir: &Path) -> Result<()> {
    let temp_dirs = [
        log_dir.join("temp"),
        log_dir.join("service").join("temp"),
        log_dir.join("sidecar").join("temp"),
    ];

    for temp_dir in temp_dirs.iter().filter(|d| d.exists()) {
        let mut entries = fs::read_dir(temp_dir).await?;
        while let Some(entry) = entries.next_entry().await? {
            let path = entry.path();
            if path.extension().and_then(|s| s.to_str()) == Some("log") {
                let _ = path.remove_if_exists().await;
                logging!(debug, Type::Setup, "delete snapshot log file: {}", path.display());
            }
        }
    }

    Ok(())
}

// TODO flexi_logger 提供了最大保留天数，或许我们应该用内置删除log文件
pub async fn delete_log() -> Result<()> {
    let log_dir = dirs::app_logs_dir()?;
    let service_log_dir = dirs::service_log_dir()?;

    if !log_dir.exists() && !service_log_dir.exists() {
        return Ok(());
    }

    #[cfg(target_os = "windows")]
    if log_dir.exists() {
        delete_snapshot_logs(&log_dir).await?;
    }

    let auto_log_clean = {
        let verge = Config::verge().await;
        let verge = verge.data_arc();
        verge.auto_log_clean.unwrap_or(0)
    };

    let day = match auto_log_clean {
        1 => 1,
        2 => 7,
        3 => 30,
        4 => 90,
        _ => return Ok(()),
    };

    logging!(debug, Type::Setup, "try to delete log files, day: {}", day);

    let parse_time_str = |s: &str| {
        let sa: Vec<&str> = s.split('-').collect();
        if sa.len() != 4 {
            return Err(anyhow::anyhow!("invalid time str"));
        }

        let year = i32::from_str(sa[0])?;
        let month = u32::from_str(sa[1])?;
        let day = u32::from_str(sa[2])?;
        let time = chrono::NaiveDate::from_ymd_opt(year, month, day)
            .ok_or_else(|| anyhow::anyhow!("invalid time str"))?
            .and_hms_opt(0, 0, 0)
            .ok_or_else(|| anyhow::anyhow!("invalid time str"))?;
        Ok(time)
    };

    let process_file = async move |file: DirEntry| -> Result<()> {
        let file_name = file.file_name();
        let file_name = file_name.to_str().unwrap_or_default();

        if file_name.ends_with(".log") {
            let now = Local::now();
            let created_time = parse_time_str(&file_name[0..file_name.len() - 4])?;
            let file_time = Local
                .from_local_datetime(&created_time)
                .single()
                .ok_or_else(|| anyhow::anyhow!("invalid local datetime"))?;

            let duration = now.signed_duration_since(file_time);
            if duration.num_days() > day {
                let _ = file.path().remove_if_exists().await;
                logging!(debug, Type::Setup, "delete log file: {}", file_name);
            }
        }
        Ok(())
    };

    if log_dir.exists() {
        let mut log_read_dir = fs::read_dir(&log_dir).await?;
        while let Some(entry) = log_read_dir.next_entry().await? {
            std::mem::drop(process_file(entry).await);
        }
    }

    if service_log_dir.exists() {
        let mut service_log_read_dir = fs::read_dir(service_log_dir).await?;
        while let Some(entry) = service_log_read_dir.next_entry().await? {
            std::mem::drop(process_file(entry).await);
        }
    }

    Ok(())
}

#[cfg(target_os = "macos")]
async fn is_logs_dir_writable(log_dir: &Path) -> bool {
    if !log_dir.is_dir() {
        logging!(warn, Type::Setup, "macOS logs path is not a directory: {:?}", log_dir);
        return false;
    }

    let probe_path = log_dir.join(format!(
        ".clash-verge-write-test-{}-{}",
        std::process::id(),
        Local::now().timestamp_nanos_opt().unwrap_or_default()
    ));

    match fs::OpenOptions::new()
        .create_new(true)
        .write(true)
        .open(&probe_path)
        .await
    {
        Ok(_) => {
            if let Err(e) = fs::remove_file(&probe_path).await {
                logging!(
                    warn,
                    Type::Setup,
                    "failed to remove macOS logs write probe {:?}: {}",
                    probe_path,
                    e
                );
            }
            true
        }
        Err(e) => {
            logging!(
                warn,
                Type::Setup,
                "macOS logs directory is not writable {:?}: {}",
                log_dir,
                e
            );
            false
        }
    }
}

#[cfg(target_os = "macos")]
fn available_legacy_path(parent: &Path, prefix: &str) -> Result<PathBuf> {
    let timestamp = Local::now().format("%Y%m%d%H%M%S");
    let base_name = format!("{prefix}-{timestamp}");
    let candidate = parent.join(&base_name);

    if !candidate.exists() {
        return Ok(candidate);
    }

    for index in 1..100 {
        let candidate = parent.join(format!("{base_name}-{index}"));
        if !candidate.exists() {
            return Ok(candidate);
        }
    }

    Err(anyhow::anyhow!(
        "failed to allocate legacy path under {:?} with prefix {}",
        parent,
        prefix
    ))
}

#[cfg(target_os = "macos")]
async fn migrate_legacy_macos_service_logs(log_dir: &Path) -> Result<()> {
    let legacy_service_dir = log_dir.join("service");
    if !legacy_service_dir.exists() {
        return Ok(());
    }

    let service_logs_root = dirs::service_logs_root_dir()?;
    fs::create_dir_all(&service_logs_root)
        .await
        .map_err(|e| anyhow::anyhow!("Failed to create service logs root {:?}: {}", service_logs_root, e))?;

    let archived_service_dir = available_legacy_path(&service_logs_root, "service.legacy")?;
    fs::rename(&legacy_service_dir, &archived_service_dir)
        .await
        .map_err(|e| {
            anyhow::anyhow!(
                "Failed to archive legacy macOS service logs {:?} to {:?}: {}",
                legacy_service_dir,
                archived_service_dir,
                e
            )
        })?;

    logging!(
        info,
        Type::Setup,
        "Archived legacy macOS service logs: {:?} -> {:?}",
        legacy_service_dir,
        archived_service_dir
    );

    Ok(())
}

/// Raise existing sub-floor update intervals, once per install.
///
/// One-off repair, not a standing rule — the UI warns about shorter intervals but still saves
/// them, so the marker is written even when nothing needed raising.
pub async fn migrate_short_update_intervals() -> Result<()> {
    let marker = dirs::update_interval_migrated_path()?;
    if fs::try_exists(&marker).await? {
        return Ok(());
    }

    // Same order as every other writer holding it (lock, then draft permit): save_file runs
    // inside the closure, ahead of the optimistic check, so a racing restore can't be undone.
    let _profile_write = crate::config::profiles::PROFILE_WRITE_LOCK.lock().await;

    let min = constants::profile::MIN_UPDATE_INTERVAL;
    let raised = Config::profiles()
        .await
        .with_data_modify(|mut profiles: IProfiles| async move {
            // `IProfiles::new` normalises items to Some when it read the file, and returns a
            // bare default() when it failed. A failed load also raises zero — without this the
            // marker would burn the one shot on profiles nobody managed to load.
            if profiles.items.is_none() {
                anyhow::bail!("profiles.yaml was not loaded; refusing to record the migration as done");
            }
            let raised = profiles.raise_short_update_intervals(min);
            if raised > 0 {
                profiles.save_file().await?;
            }
            Ok((profiles, raised))
        })
        .await?;

    if raised > 0 {
        logging!(
            info,
            Type::Setup,
            "已将 {} 个订阅的自动更新间隔提升到 {} 分钟",
            raised,
            min
        );
    }

    fs::write(&marker, b"").await?;
    Ok(())
}

#[cfg(target_os = "macos")]
async fn migrate_legacy_macos_logs() -> Result<()> {
    let log_dir = dirs::app_logs_dir()?;

    if !log_dir.exists() {
        return Ok(());
    }

    if is_logs_dir_writable(&log_dir).await {
        if let Err(e) = migrate_legacy_macos_service_logs(&log_dir).await {
            logging!(warn, Type::Setup, "Failed to migrate legacy macOS service logs: {e:#}");
        }
        return Ok(());
    }

    let app_home = dirs::app_home_dir()?;
    let archived_log_dir = available_legacy_path(&app_home, "logs.legacy-root")?;
    fs::rename(&log_dir, &archived_log_dir).await.map_err(|e| {
        anyhow::anyhow!(
            "Failed to archive unwritable macOS logs directory {:?} to {:?}: {}",
            log_dir,
            archived_log_dir,
            e
        )
    })?;

    logging!(
        warn,
        Type::Setup,
        "Archived unwritable macOS logs directory: {:?} -> {:?}",
        log_dir,
        archived_log_dir
    );

    fs::create_dir_all(&log_dir)
        .await
        .map_err(|e| anyhow::anyhow!("Failed to recreate macOS logs directory {:?}: {}", log_dir, e))?;
    logging!(info, Type::Setup, "Recreated macOS logs directory: {:?}", log_dir);

    Ok(())
}

pub(super) async fn init_dns_config() -> Result<()> {
    use serde_yaml_ng::Value;

    let dns_config = serde_yaml_ng::Mapping::from_iter([
        ("enable".into(), Value::Bool(true)),
        // Must match the frontend default used for authoritative `dns.ipv6`.
        ("ipv6".into(), Value::Bool(true)),
        ("listen".into(), Value::String(":53".into())),
        ("enhanced-mode".into(), Value::String("fake-ip".into())),
        ("fake-ip-range".into(), Value::String("198.18.0.1/16".into())),
        ("fake-ip-range6".into(), Value::String("fdfe:dcba:9876::1/64".into())),
        ("fake-ip-filter-mode".into(), Value::String("blacklist".into())),
        ("prefer-h3".into(), Value::Bool(false)),
        ("respect-rules".into(), Value::Bool(false)),
        ("use-hosts".into(), Value::Bool(false)),
        ("use-system-hosts".into(), Value::Bool(false)),
        (
            "fake-ip-filter".into(),
            Value::Sequence(vec![
                Value::String("*.lan".into()),
                Value::String("*.local".into()),
                Value::String("*.arpa".into()),
                Value::String("time.*.com".into()),
                Value::String("ntp.*.com".into()),
                Value::String("time.*.com".into()),
                Value::String("+.market.xiaomi.com".into()),
                Value::String("localhost.ptlogin2.qq.com".into()),
                Value::String("*.msftncsi.com".into()),
                Value::String("www.msftconnecttest.com".into()),
            ]),
        ),
        (
            "default-nameserver".into(),
            Value::Sequence(vec![
                Value::String("system".into()),
                Value::String("223.6.6.6".into()),
                Value::String("8.8.8.8".into()),
                Value::String("2400:3200::1".into()),
                Value::String("2001:4860:4860::8888".into()),
            ]),
        ),
        (
            "nameserver".into(),
            Value::Sequence(vec![
                Value::String("8.8.8.8".into()),
                Value::String("https://doh.pub/dns-query".into()),
                Value::String("https://dns.alidns.com/dns-query".into()),
            ]),
        ),
        ("fallback".into(), Value::Sequence(vec![])),
        (
            "nameserver-policy".into(),
            Value::Mapping(serde_yaml_ng::Mapping::new()),
        ),
        (
            "proxy-server-nameserver".into(),
            Value::Sequence(vec![
                Value::String("https://doh.pub/dns-query".into()),
                Value::String("https://dns.alidns.com/dns-query".into()),
                Value::String("tls://223.5.5.5".into()),
            ]),
        ),
        ("direct-nameserver".into(), Value::Sequence(vec![])),
        ("direct-nameserver-follow-policy".into(), Value::Bool(false)),
        (
            "fallback-filter".into(),
            Value::Mapping(serde_yaml_ng::Mapping::from_iter([
                ("geoip".into(), Value::Bool(true)),
                ("geoip-code".into(), Value::String("CN".into())),
                (
                    "ipcidr".into(),
                    Value::Sequence(vec![
                        Value::String("240.0.0.0/4".into()),
                        Value::String("0.0.0.0/32".into()),
                    ]),
                ),
                (
                    "domain".into(),
                    Value::Sequence(vec![
                        Value::String("+.google.com".into()),
                        Value::String("+.facebook.com".into()),
                        Value::String("+.youtube.com".into()),
                    ]),
                ),
            ])),
        ),
    ]);

    let default_dns_config = serde_yaml_ng::Mapping::from_iter([
        ("dns".into(), Value::Mapping(dns_config)),
        ("hosts".into(), Value::Mapping(serde_yaml_ng::Mapping::new())),
    ]);

    let app_dir = dirs::app_home_dir()?;
    let dns_path = app_dir.join(constants::files::DNS_CONFIG);

    if !dns_path.exists() {
        logging!(info, Type::Setup, "Creating default DNS config file");
        help::save_yaml(&dns_path, &default_dns_config, Some("# Clash Verge DNS Config")).await?;
    }

    Ok(())
}

async fn ensure_directories() -> Result<()> {
    let directories = [
        ("app_home", dirs::app_home_dir()?),
        ("app_profiles", dirs::app_profiles_dir()?),
        ("app_logs", dirs::app_logs_dir()?),
        ("service_logs", dirs::service_log_dir()?),
    ];

    for (name, dir) in directories {
        if !dir.exists() {
            fs::create_dir_all(&dir)
                .await
                .map_err(|e| anyhow::anyhow!("Failed to create {} directory {:?}: {}", name, dir, e))?;
            logging!(info, Type::Setup, "Created {} directory: {:?}", name, dir);
        }
    }

    Ok(())
}

async fn initialize_config_files() -> Result<()> {
    if let Ok(path) = dirs::clash_path()
        && !path.exists()
    {
        let template = IClashTemp::template().0;
        help::save_yaml(&path, &template, Some("# Clash Verge"))
            .await
            .map_err(|e| anyhow::anyhow!("Failed to create clash config: {}", e))?;
        logging!(info, Type::Setup, "Created clash config at {:?}", path);
    }

    if let Ok(path) = dirs::verge_path()
        && !path.exists()
    {
        let template = IVerge::template();
        help::save_yaml(&path, &template, Some("# Clash Verge"))
            .await
            .map_err(|e| anyhow::anyhow!("Failed to create verge config: {}", e))?;
        logging!(info, Type::Setup, "Created verge config at {:?}", path);
    }

    if let Ok(path) = dirs::profiles_path()
        && !path.exists()
    {
        let template = IProfiles::default();
        help::save_yaml(&path, &template, Some("# Clash Verge"))
            .await
            .map_err(|e| anyhow::anyhow!("Failed to create profiles config: {}", e))?;
        logging!(info, Type::Setup, "Created profiles config at {:?}", path);
    }

    IVerge::validate_and_fix_config()
        .await
        .map_err(|e| anyhow::anyhow!("Failed to validate verge config: {}", e))?;

    Ok(())
}

/// Initializes configuration required before Tauri setup.
pub async fn init_config() -> Result<()> {
    #[cfg(target_os = "macos")]
    migrate_legacy_macos_logs().await?;

    ensure_directories().await?;

    initialize_config_files().await?;

    AsyncHandler::spawn(|| async {
        if let Err(e) = delete_log().await {
            logging!(warn, Type::Setup, "Failed to clean old logs: {e:#}");
        }
        logging!(debug, Type::Setup, "后台日志清理任务完成");
    });

    Ok(())
}

/// Initializes application resources after Tauri setup.
pub async fn init_resources() -> Result<()> {
    let app_dir = dirs::app_home_dir()?;
    let res_dir = dirs::app_resources_dir()?;

    if !app_dir.exists() {
        std::mem::drop(fs::create_dir_all(&app_dir).await);
    }
    if !res_dir.exists() {
        std::mem::drop(fs::create_dir_all(&res_dir).await);
    }

    let file_list = ["Country.mmdb", "geoip.dat", "geosite.dat"];

    for file in file_list.iter() {
        let src_path = res_dir.join(file);
        let dest_path = app_dir.join(file);

        if src_path.exists() && !dest_path.exists() {
            handle_copy(&src_path, &dest_path, file).await;
            continue;
        }

        let src_modified = fs::metadata(&src_path).await.and_then(|m| m.modified());
        let dest_modified = fs::metadata(&dest_path).await.and_then(|m| m.modified());

        match (src_modified, dest_modified) {
            (Ok(src_modified), Ok(dest_modified)) => {
                if src_modified > dest_modified {
                    handle_copy(&src_path, &dest_path, file).await;
                }
            }
            _ => {
                logging!(debug, Type::Setup, "failed to get modified '{}'", file);
                handle_copy(&src_path, &dest_path, file).await;
            }
        };
    }

    Ok(())
}

#[cfg(target_os = "windows")]
pub fn init_scheme() -> Result<()> {
    use tauri::utils::platform::current_exe;
    use winreg::{RegKey, enums::HKEY_CURRENT_USER};

    let app_exe = current_exe()?;
    let app_exe = dunce::canonicalize(app_exe)?;
    let app_exe = app_exe.to_string_lossy().into_owned();

    let hkcu = RegKey::predef(HKEY_CURRENT_USER);
    let (clash, _) = hkcu.create_subkey("Software\\Classes\\Clash")?;
    clash.set_value("", &"Clash Verge")?;
    clash.set_value("URL Protocol", &"Clash Verge URL Scheme Protocol")?;
    let (default_icon, _) = hkcu.create_subkey("Software\\Classes\\Clash\\DefaultIcon")?;
    default_icon.set_value("", &app_exe)?;
    let (command, _) = hkcu.create_subkey("Software\\Classes\\Clash\\Shell\\Open\\Command")?;
    command.set_value("", &format!("{app_exe} \"%1\""))?;

    Ok(())
}
#[cfg(target_os = "linux")]
pub fn init_scheme() -> Result<()> {
    const DESKTOP_FILE: &str = "clash-verge.desktop";

    for scheme in DEEP_LINK_SCHEMES {
        let handler = format!("x-scheme-handler/{scheme}");
        let output = std::process::Command::new("xdg-mime")
            .arg("default")
            .arg(DESKTOP_FILE)
            .arg(&handler)
            .output()?;
        if !output.status.success() {
            return Err(anyhow::anyhow!(
                "failed to set {handler}, {}",
                String::from_utf8_lossy(&output.stderr)
            ));
        }
    }

    crate::utils::linux::mime::ensure_mimeapps_entries(DESKTOP_FILE, DEEP_LINK_SCHEMES)?;
    Ok(())
}
#[cfg(target_os = "macos")]
pub const fn init_scheme() -> Result<()> {
    Ok(())
}

#[cfg(target_os = "linux")]
const DEEP_LINK_SCHEMES: &[&str] = &["clash", "clash-verge"];

pub async fn startup_script() -> Result<()> {
    let app_handle = handle::Handle::app_handle();
    let script_path = {
        let verge = Config::verge().await;
        let verge = verge.data_arc();
        verge.startup_script.clone().unwrap_or_else(|| "".into())
    };

    if script_path.is_empty() {
        return Ok(());
    }

    let shell_type = if script_path.ends_with(".sh") {
        "bash"
    } else if script_path.ends_with(".ps1") || script_path.ends_with(".bat") {
        "powershell"
    } else {
        return Err(anyhow::anyhow!("unsupported script extension: {}", script_path));
    };

    let script_dir = PathBuf::from(script_path.as_str());
    if !script_dir.exists() {
        return Err(anyhow::anyhow!("script not found: {}", script_path));
    }

    let parent_dir = script_dir.parent();
    let working_dir = parent_dir.unwrap_or_else(|| script_dir.as_ref());

    app_handle
        .shell()
        .command(shell_type)
        .current_dir(working_dir)
        .args([script_path.as_str()])
        .output()
        .await?;

    Ok(())
}

async fn handle_copy(src: &PathBuf, dest: &PathBuf, file: &str) {
    match fs::copy(src, dest).await {
        Ok(_) => {
            logging!(debug, Type::Setup, "resources copied '{}'", file);
        }
        Err(err) => {
            logging!(
                error,
                Type::Setup,
                "failed to copy resources '{}' to '{:?}', {}",
                file,
                dest,
                err
            );
        }
    };
}