// SPDX-License-Identifier: MIT OR Apache-2.0
// This file is part of Static Web Server.
// See https://static-web-server.net/ for more information
// Copyright (C) 2019-present Jose Quintana <joseluisq.net>

//! Module that provides all settings of SWS.
//!

use clap::Parser;
use globset::{Glob, GlobMatcher};
use headers::HeaderMap;
use hyper::StatusCode;
use regex::Regex;

use crate::{Context, Result};

pub mod cli;
pub mod file;

#[cfg(windows)]
pub use cli::Commands;

use cli::General;

use self::file::RedirectsKind;

/// The `headers` file options.
pub struct Headers {
    /// Source pattern glob matcher
    pub source: GlobMatcher,
    /// Map of custom HTTP headers
    pub headers: HeaderMap,
}

/// The `Rewrites` file options.
pub struct Rewrites {
    /// Source pattern Regex matcher
    pub source: Regex,
    /// A local file that must exist
    pub destination: String,
    /// Optional redirect type either 301 (Moved Permanently) or 302 (Found).
    pub redirect: Option<RedirectsKind>,
}

/// The `Redirects` file options.
pub struct Redirects {
    /// Source pattern Regex matcher
    pub source: Regex,
    /// A local file that must exist
    pub destination: String,
    /// Redirection type either 301 (Moved Permanently) or 302 (Found)
    pub kind: StatusCode,
}

/// The `advanced` file options.
pub struct Advanced {
    /// Headers list.
    pub headers: Option<Vec<Headers>>,
    /// Rewrites list.
    pub rewrites: Option<Vec<Rewrites>>,
    /// Redirects list.
    pub redirects: Option<Vec<Redirects>>,
}

/// The full server CLI and File options.
pub struct Settings {
    /// General server options
    pub general: General,
    /// Advanced server options
    pub advanced: Option<Advanced>,
}

impl Settings {
    /// Handles CLI and config file options and converging them into one.
    pub fn get() -> Result<Settings> {
        let opts = General::parse();

        // Define the general CLI/file options
        let mut host = opts.host;
        let mut port = opts.port;
        let mut root = opts.root;
        let mut log_level = opts.log_level;
        let mut config_file = opts.config_file.clone();
        let mut cache_control_headers = opts.cache_control_headers;

        #[cfg(feature = "compression")]
        let mut compression = opts.compression;
        #[cfg(feature = "compression")]
        let mut compression_static = opts.compression_static;

        let mut page404 = opts.page404;
        let mut page50x = opts.page50x;

        #[cfg(feature = "http2")]
        let mut http2 = opts.http2;
        #[cfg(feature = "http2")]
        let mut http2_tls_cert = opts.http2_tls_cert;
        #[cfg(feature = "http2")]
        let mut http2_tls_key = opts.http2_tls_key;
        #[cfg(feature = "http2")]
        let mut https_redirect = opts.https_redirect;
        #[cfg(feature = "http2")]
        let mut https_redirect_host = opts.https_redirect_host;
        #[cfg(feature = "http2")]
        let mut https_redirect_from_port = opts.https_redirect_from_port;
        #[cfg(feature = "http2")]
        let mut https_redirect_from_hosts = opts.https_redirect_from_hosts;

        let mut security_headers = opts.security_headers;
        let mut cors_allow_origins = opts.cors_allow_origins;
        let mut cors_allow_headers = opts.cors_allow_headers;
        let mut cors_expose_headers = opts.cors_expose_headers;

        #[cfg(feature = "directory-listing")]
        let mut directory_listing = opts.directory_listing;
        #[cfg(feature = "directory-listing")]
        let mut directory_listing_order = opts.directory_listing_order;
        #[cfg(feature = "directory-listing")]
        let mut directory_listing_format = opts.directory_listing_format;

        #[cfg(feature = "basic-auth")]
        let mut basic_auth = opts.basic_auth;

        let mut fd = opts.fd;
        let mut threads_multiplier = opts.threads_multiplier;
        let mut max_blocking_threads = opts.max_blocking_threads;
        let mut grace_period = opts.grace_period;

        #[cfg(feature = "fallback-page")]
        let mut page_fallback = opts.page_fallback;

        let mut log_remote_address = opts.log_remote_address;
        let mut redirect_trailing_slash = opts.redirect_trailing_slash;
        let mut ignore_hidden_files = opts.ignore_hidden_files;
        let mut health = opts.health;

        // Windows-only options
        #[cfg(windows)]
        let mut windows_service = opts.windows_service;

        // Define the advanced file options
        let mut settings_advanced: Option<Advanced> = None;

        // Handle "config file options" and set them when available
        // NOTE: All config file based options shouldn't be mandatory, therefore `Some()` wrapped
        if let Some(ref p) = opts.config_file {
            if p.is_file() {
                let path_resolved = p
                    .canonicalize()
                    .with_context(|| "error resolving toml config file path")?;

                let settings = file::Settings::read(&path_resolved)
                    .with_context(|| {
                        "can not read toml config file because has invalid or unsupported format/options"
                    })?;

                config_file = Some(path_resolved);

                // File-based "general" options
                if let Some(general) = settings.general {
                    if let Some(v) = general.host {
                        host = v
                    }
                    if let Some(v) = general.port {
                        port = v
                    }
                    if let Some(v) = general.root {
                        root = v
                    }
                    if let Some(ref v) = general.log_level {
                        log_level = v.name().to_lowercase();
                    }
                    if let Some(v) = general.cache_control_headers {
                        cache_control_headers = v
                    }
                    #[cfg(feature = "compression")]
                    if let Some(v) = general.compression {
                        compression = v
                    }
                    #[cfg(feature = "compression")]
                    if let Some(v) = general.compression_static {
                        compression_static = v
                    }
                    if let Some(v) = general.page404 {
                        page404 = v
                    }
                    if let Some(v) = general.page50x {
                        page50x = v
                    }
                    #[cfg(feature = "http2")]
                    if let Some(v) = general.http2 {
                        http2 = v
                    }
                    #[cfg(feature = "http2")]
                    if let Some(v) = general.http2_tls_cert {
                        http2_tls_cert = Some(v)
                    }
                    #[cfg(feature = "http2")]
                    if let Some(v) = general.http2_tls_key {
                        http2_tls_key = Some(v)
                    }
                    #[cfg(feature = "http2")]
                    if let Some(v) = general.https_redirect {
                        https_redirect = v
                    }
                    #[cfg(feature = "http2")]
                    if let Some(v) = general.https_redirect_host {
                        https_redirect_host = v
                    }
                    #[cfg(feature = "http2")]
                    if let Some(v) = general.https_redirect_from_port {
                        https_redirect_from_port = v
                    }
                    #[cfg(feature = "http2")]
                    if let Some(v) = general.https_redirect_from_hosts {
                        https_redirect_from_hosts = v
                    }
                    #[cfg(feature = "http2")]
                    match general.security_headers {
                        Some(v) => security_headers = v,
                        _ => {
                            if http2 {
                                security_headers = true;
                            }
                        }
                    }
                    #[cfg(not(feature = "http2"))]
                    if let Some(v) = general.security_headers {
                        security_headers = v
                    }
                    if let Some(ref v) = general.cors_allow_origins {
                        cors_allow_origins = v.to_owned()
                    }
                    if let Some(ref v) = general.cors_allow_headers {
                        cors_allow_headers = v.to_owned()
                    }
                    if let Some(ref v) = general.cors_expose_headers {
                        cors_expose_headers = v.to_owned()
                    }
                    #[cfg(feature = "directory-listing")]
                    if let Some(v) = general.directory_listing {
                        directory_listing = v
                    }
                    #[cfg(feature = "directory-listing")]
                    if let Some(v) = general.directory_listing_order {
                        directory_listing_order = v
                    }
                    #[cfg(feature = "directory-listing")]
                    if let Some(v) = general.directory_listing_format {
                        directory_listing_format = v
                    }
                    #[cfg(feature = "basic-auth")]
                    if let Some(ref v) = general.basic_auth {
                        basic_auth = v.to_owned()
                    }
                    if let Some(v) = general.fd {
                        fd = Some(v)
                    }
                    if let Some(v) = general.threads_multiplier {
                        threads_multiplier = v
                    }
                    if let Some(v) = general.max_blocking_threads {
                        max_blocking_threads = v
                    }
                    if let Some(v) = general.grace_period {
                        grace_period = v
                    }
                    #[cfg(feature = "fallback-page")]
                    if let Some(v) = general.page_fallback {
                        page_fallback = v
                    }
                    if let Some(v) = general.log_remote_address {
                        log_remote_address = v
                    }
                    if let Some(v) = general.redirect_trailing_slash {
                        redirect_trailing_slash = v
                    }
                    if let Some(v) = general.ignore_hidden_files {
                        ignore_hidden_files = v
                    }
                    if let Some(v) = general.health {
                        health = v
                    }

                    // Windows-only options
                    #[cfg(windows)]
                    if let Some(v) = general.windows_service {
                        windows_service = v
                    }
                }

                // File-based "advanced" options
                if let Some(advanced) = settings.advanced {
                    // 1. Custom HTTP headers assignment
                    let headers_entries = match advanced.headers {
                        Some(headers_entries) => {
                            let mut headers_vec: Vec<Headers> = Vec::new();

                            // Compile a glob pattern for each header sources entry
                            for headers_entry in headers_entries.iter() {
                                let source = Glob::new(&headers_entry.source)
                                    .with_context(|| {
                                        format!(
                                            "can not compile glob pattern for header source: {}",
                                            &headers_entry.source
                                        )
                                    })?
                                    .compile_matcher();

                                headers_vec.push(Headers {
                                    source,
                                    headers: headers_entry.headers.to_owned(),
                                });
                            }
                            Some(headers_vec)
                        }
                        _ => None,
                    };

                    // 2. Rewrites assignment
                    let rewrites_entries = match advanced.rewrites {
                        Some(rewrites_entries) => {
                            let mut rewrites_vec: Vec<Rewrites> = Vec::new();

                            // Compile a glob pattern for each rewrite sources entry
                            for rewrites_entry in rewrites_entries.iter() {
                                let source = Glob::new(&rewrites_entry.source)
                                    .with_context(|| {
                                        format!(
                                            "can not compile glob pattern for rewrite source: {}",
                                            &rewrites_entry.source
                                        )
                                    })?
                                    .compile_matcher();

                                // NOTE: we don’t need Unicode-aware word boundary assertions,
                                // therefore we use (?-u:\b) instead of (?-u)
                                // so the former uses an ASCII-only definition of a word character.
                                // https://docs.rs/regex/latest/regex/#unicode-can-impact-memory-usage-and-search-speed
                                let pattern = source.glob().regex().replace("(?-u)^", "(?-u:\\b)");
                                tracing::debug!(
                                    "url rewrites glob pattern: {}",
                                    &rewrites_entry.source
                                );
                                tracing::debug!("url rewrites regex equivalent: {}", pattern);

                                let source = Regex::new(&pattern).with_context(|| {
                                    format!(
                                        "can not compile regex pattern equivalent for rewrite source: {}",
                                        &pattern
                                    )
                                })?;

                                rewrites_vec.push(Rewrites {
                                    source,
                                    destination: rewrites_entry.destination.to_owned(),
                                    redirect: rewrites_entry.redirect.to_owned(),
                                });
                            }
                            Some(rewrites_vec)
                        }
                        _ => None,
                    };

                    // 3. Redirects assignment
                    let redirects_entries = match advanced.redirects {
                        Some(redirects_entries) => {
                            let mut redirects_vec: Vec<Redirects> = Vec::new();

                            // Compile a glob pattern for each redirect sources entry
                            for redirects_entry in redirects_entries.iter() {
                                let source = Glob::new(&redirects_entry.source)
                                    .with_context(|| {
                                        format!(
                                            "can not compile glob pattern for redirect source: {}",
                                            &redirects_entry.source
                                        )
                                    })?
                                    .compile_matcher();

                                // NOTE: we don’t need Unicode-aware word boundary assertions,
                                // therefore we use (?-u:\b) instead of (?-u)
                                // so the former uses an ASCII-only definition of a word character.
                                // https://docs.rs/regex/latest/regex/#unicode-can-impact-memory-usage-and-search-speed
                                let pattern = source.glob().regex().replace("(?-u)^", "(?-u:\\b)");
                                tracing::debug!(
                                    "url rewrites glob pattern: {}",
                                    &redirects_entry.source
                                );
                                tracing::debug!("url rewrites regex equivalent: {}", pattern);

                                let source = Regex::new(&pattern).with_context(|| {
                                    format!(
                                        "can not compile regex pattern equivalent for rewrite source: {}",
                                        &pattern
                                    )
                                })?;

                                let status_code = redirects_entry.kind.to_owned() as u16;
                                redirects_vec.push(Redirects {
                                    source,
                                    destination: redirects_entry.destination.to_owned(),
                                    kind: StatusCode::from_u16(status_code).with_context(|| {
                                        format!("invalid redirect status code: {status_code}")
                                    })?,
                                });
                            }
                            Some(redirects_vec)
                        }
                        _ => None,
                    };

                    settings_advanced = Some(Advanced {
                        headers: headers_entries,
                        rewrites: rewrites_entries,
                        redirects: redirects_entries,
                    });
                }
            }
        }

        Ok(Settings {
            general: General {
                host,
                port,
                root,
                log_level,
                config_file,
                cache_control_headers,
                #[cfg(feature = "compression")]
                compression,
                #[cfg(feature = "compression")]
                compression_static,
                page404,
                page50x,
                #[cfg(feature = "http2")]
                http2,
                #[cfg(feature = "http2")]
                http2_tls_cert,
                #[cfg(feature = "http2")]
                http2_tls_key,
                #[cfg(feature = "http2")]
                https_redirect,
                #[cfg(feature = "http2")]
                https_redirect_host,
                #[cfg(feature = "http2")]
                https_redirect_from_port,
                #[cfg(feature = "http2")]
                https_redirect_from_hosts,
                security_headers,
                cors_allow_origins,
                cors_allow_headers,
                cors_expose_headers,
                #[cfg(feature = "directory-listing")]
                directory_listing,
                #[cfg(feature = "directory-listing")]
                directory_listing_order,
                #[cfg(feature = "directory-listing")]
                directory_listing_format,
                #[cfg(feature = "basic-auth")]
                basic_auth,
                fd,
                threads_multiplier,
                max_blocking_threads,
                grace_period,
                #[cfg(feature = "fallback-page")]
                page_fallback,
                log_remote_address,
                redirect_trailing_slash,
                ignore_hidden_files,
                health,

                // Windows-only options and commands
                #[cfg(windows)]
                windows_service,
                #[cfg(windows)]
                commands: opts.commands,
            },
            advanced: settings_advanced,
        })
    }
}