use std::path::{Path, PathBuf};
use std::time::SystemTime;
#[cfg(target_family = "unix")]
use std::{fs, os::unix::fs::MetadataExt};

use crate::common::Common;
use crate::common_messages::Messages;
use crate::flc;
use crate::localizer_core::generate_translation_hashmap;

#[derive(Clone, Default)]
pub struct Directories {
    pub excluded_directories: Vec<PathBuf>,
    pub included_directories: Vec<PathBuf>,
    pub reference_directories: Vec<PathBuf>,
    exclude_other_filesystems: Option<bool>,
    #[cfg(target_family = "unix")]
    included_dev_ids: Vec<u64>,
}

impl Directories {
    #[must_use]
    pub fn new() -> Self {
        Default::default()
    }

    pub fn set_reference_directory(&mut self, reference_directory: Vec<PathBuf>) {
        self.reference_directories = reference_directory;
    }

    /// Setting included directories, at least one must be provided or scan won't start
    pub fn set_included_directory(&mut self, included_directory: Vec<PathBuf>, text_messages: &mut Messages) -> bool {
        let start_time: SystemTime = SystemTime::now();

        if included_directory.is_empty() {
            text_messages.errors.push(flc!("core_missing_no_chosen_included_directory"));
            return false;
        }

        let directories: Vec<PathBuf> = included_directory;

        let mut checked_directories: Vec<PathBuf> = Vec::new();
        for directory in directories {
            if directory.to_string_lossy().contains('*') {
                text_messages.warnings.push(flc!(
                    "core_directory_wildcard_no_supported",
                    generate_translation_hashmap(vec![("path", directory.display().to_string())])
                ));
                continue;
            }

            #[cfg(not(target_family = "windows"))]
            if directory.is_relative() {
                text_messages.warnings.push(flc!(
                    "core_directory_relative_path",
                    generate_translation_hashmap(vec![("path", directory.display().to_string())])
                ));
                continue;
            }
            #[cfg(target_family = "windows")]
            if directory.is_relative() && !directory.starts_with("\\") {
                text_messages.warnings.push(flc!(
                    "core_directory_relative_path",
                    generate_translation_hashmap(vec![("path", directory.display().to_string())])
                ));
                continue;
            }

            if !directory.exists() {
                text_messages.warnings.push(flc!(
                    "core_directory_must_exists",
                    generate_translation_hashmap(vec![("path", directory.display().to_string())])
                ));
                continue;
            }
            if !directory.is_dir() {
                text_messages.warnings.push(flc!(
                    "core_directory_must_be_directory",
                    generate_translation_hashmap(vec![("path", directory.display().to_string())])
                ));
                continue;
            }
            checked_directories.push(directory);
        }

        if checked_directories.is_empty() {
            text_messages.warnings.push(flc!("core_included_directory_zero_valid_directories"));
            return false;
        }

        self.included_directories = checked_directories;

        Common::print_time(start_time, SystemTime::now(), "set_included_directory");
        true
    }

    /// Setting absolute path to exclude from search
    pub fn set_excluded_directory(&mut self, excluded_directory: Vec<PathBuf>, text_messages: &mut Messages) {
        let start_time: SystemTime = SystemTime::now();
        if excluded_directory.is_empty() {
            return;
        }

        let directories: Vec<PathBuf> = excluded_directory;

        let mut checked_directories: Vec<PathBuf> = Vec::new();
        for directory in directories {
            let directory_as_string = directory.to_string_lossy();
            if directory_as_string == "/" {
                text_messages.errors.push(flc!("core_excluded_directory_pointless_slash"));
                break;
            }
            if directory_as_string.contains('*') {
                text_messages.warnings.push(flc!(
                    "core_directory_wildcard_no_supported",
                    generate_translation_hashmap(vec![("path", directory.display().to_string())])
                ));
                continue;
            }
            #[cfg(not(target_family = "windows"))]
            if directory.is_relative() {
                text_messages.warnings.push(flc!(
                    "core_directory_relative_path",
                    generate_translation_hashmap(vec![("path", directory.display().to_string())])
                ));
                continue;
            }
            #[cfg(target_family = "windows")]
            if directory.is_relative() && !directory.starts_with("\\") {
                text_messages.warnings.push(flc!(
                    "core_directory_relative_path",
                    generate_translation_hashmap(vec![("path", directory.display().to_string())])
                ));
                continue;
            }

            if !directory.exists() {
                // No error when excluded directories are missing
                continue;
            }
            if !directory.is_dir() {
                text_messages.warnings.push(flc!(
                    "core_directory_must_be_directory",
                    generate_translation_hashmap(vec![("path", directory.display().to_string())])
                ));
                continue;
            }
            checked_directories.push(directory);
        }
        self.excluded_directories = checked_directories;

        Common::print_time(start_time, SystemTime::now(), "set_excluded_directory");
    }

    #[cfg(target_family = "unix")]
    pub fn set_exclude_other_filesystems(&mut self, exclude_other_filesystems: bool) {
        self.exclude_other_filesystems = Some(exclude_other_filesystems);
    }

    /// Remove unused entries when included or excluded overlaps with each other or are duplicated etc.
    pub fn optimize_directories(&mut self, recursive_search: bool, text_messages: &mut Messages) -> bool {
        let start_time: SystemTime = SystemTime::now();

        let mut optimized_included: Vec<PathBuf> = Vec::new();
        let mut optimized_excluded: Vec<PathBuf> = Vec::new();

        if cfg!(target_family = "windows") {
            self.included_directories = self.included_directories.iter().map(Common::normalize_windows_path).collect();
            self.excluded_directories = self.excluded_directories.iter().map(Common::normalize_windows_path).collect();
            self.reference_directories = self.reference_directories.iter().map(Common::normalize_windows_path).collect();
        }

        // Remove duplicated entries like: "/", "/"

        self.excluded_directories.sort_unstable();
        self.included_directories.sort_unstable();
        self.reference_directories.sort_unstable();

        self.excluded_directories.dedup();
        self.included_directories.dedup();
        self.reference_directories.dedup();

        // Optimize for duplicated included directories - "/", "/home". "/home/Pulpit" to "/"
        // Do not use when not using recursive search or using
        if recursive_search && !self.exclude_other_filesystems.unwrap_or(false) {
            // This is only point which can't be done when recursive search is disabled.
            let mut is_inside: bool;
            for ed_checked in &self.excluded_directories {
                is_inside = false;
                for ed_help in &self.excluded_directories {
                    if ed_checked == ed_help {
                        // We checking same element
                        continue;
                    }
                    if ed_checked.starts_with(ed_help) {
                        is_inside = true;
                        break;
                    }
                }
                if !is_inside {
                    optimized_excluded.push(ed_checked.clone());
                }
            }

            for id_checked in &self.included_directories {
                is_inside = false;
                for id_help in &self.included_directories {
                    if id_checked == id_help {
                        // We checking same element
                        continue;
                    }
                    if id_checked.starts_with(id_help) {
                        is_inside = true;
                        break;
                    }
                }
                if !is_inside {
                    optimized_included.push(id_checked.clone());
                }
            }

            self.included_directories = optimized_included;
            optimized_included = Vec::new();
            self.excluded_directories = optimized_excluded;
            optimized_excluded = Vec::new();
        }

        // Remove included directories which are inside any excluded directory
        for id in &self.included_directories {
            let mut is_inside: bool = false;
            for ed in &self.excluded_directories {
                if id.starts_with(ed) {
                    is_inside = true;
                    break;
                }
            }
            if !is_inside {
                optimized_included.push(id.clone());
            }
        }
        self.included_directories = optimized_included;
        optimized_included = Vec::new();

        // Remove non existed directories
        for id in &self.included_directories {
            let path = Path::new(id);
            if path.exists() {
                optimized_included.push(id.clone());
            }
        }

        for ed in &self.excluded_directories {
            let path = Path::new(ed);
            if path.exists() {
                optimized_excluded.push(ed.clone());
            }
        }

        self.included_directories = optimized_included;
        self.excluded_directories = optimized_excluded;
        optimized_excluded = Vec::new();

        // Excluded paths must are inside included path, because
        for ed in &self.excluded_directories {
            let mut is_inside: bool = false;
            for id in &self.included_directories {
                if ed.starts_with(id) {
                    is_inside = true;
                    break;
                }
            }
            if is_inside {
                optimized_excluded.push(ed.clone());
            }
        }

        self.excluded_directories = optimized_excluded;

        // Selecting Reference folders
        {
            let mut ref_folders = Vec::new();
            for folder in &self.reference_directories {
                if self.included_directories.iter().any(|e| folder.starts_with(e)) {
                    ref_folders.push(folder.clone());
                }
            }
            self.reference_directories = ref_folders;
        }

        if self.included_directories.is_empty() {
            text_messages.errors.push(flc!("core_directory_overlap"));
            return false;
        }

        // Not needed, but better is to have sorted everything
        self.excluded_directories.sort_unstable();
        self.included_directories.sort_unstable();
        Common::print_time(start_time, SystemTime::now(), "optimize_directories");

        // Get device IDs for included directories
        #[cfg(target_family = "unix")]
        if self.exclude_other_filesystems() {
            for d in &self.included_directories {
                match fs::metadata(d) {
                    Ok(m) => self.included_dev_ids.push(m.dev()),
                    Err(_) => text_messages.errors.push(flc!(
                        "core_directory_unable_to_get_device_id",
                        generate_translation_hashmap(vec![("path", d.display().to_string())])
                    )),
                }
            }
        }

        true
    }

    /// Checks whether a specified directory is excluded from searching
    pub fn is_excluded(&self, path: impl AsRef<Path>) -> bool {
        let path = path.as_ref();
        #[cfg(target_family = "windows")]
        let path = Common::normalize_windows_path(path);
        // We're assuming that `excluded_directories` are already normalized
        self.excluded_directories.iter().any(|p| p.as_path() == path)
    }

    #[cfg(target_family = "unix")]
    #[must_use]
    pub fn exclude_other_filesystems(&self) -> bool {
        self.exclude_other_filesystems.unwrap_or(false)
    }

    /// Checks whether a specified directory is on other filesystems rather then include
    /// directories
    #[cfg(target_family = "unix")]
    pub fn is_on_other_filesystems(&self, path: impl AsRef<Path>) -> Result<bool, String> {
        let path = path.as_ref();
        match fs::metadata(path) {
            Ok(m) => Ok(!self.included_dev_ids.iter().any(|&id| id == m.dev())),
            Err(_) => Err(flc!(
                "core_directory_unable_to_get_device_id",
                generate_translation_hashmap(vec![("path", path.display().to_string())])
            )),
        }
    }
}