use crate::event::LoadingBarType;
use crate::event::emit::{
    emit_loading, init_or_edit_loading, loading_try_for_each_concurrent,
};
use crate::pack::install_from::{
    EnvType, PackFile, PackFileHash, set_profile_information,
};
use crate::state::{
    CacheBehaviour, CachedEntry, ProfileInstallStage, SideType, cache_file_hash,
};
use crate::util::fetch::{fetch_mirrors, write};
use crate::util::io;
use crate::{State, profile};
use async_zip::base::read::seek::ZipFileReader;
use futures::StreamExt;
use path_util::SafeRelativeUtf8UnixPathBuf;

use super::install_from::{
    CreatePack, CreatePackLocation, PackFormat, generate_pack_from_file,
    generate_pack_from_version_id,
};
use crate::data::ProjectType;
use std::io::{Cursor, ErrorKind};

/// Install a pack
/// Wrapper around install_pack_files that generates a pack creation description, and
/// attempts to install the pack files. If it fails, it will remove the profile (fail safely)
/// Install a modpack from a mrpack file (a modrinth .zip format)
pub async fn install_zipped_mrpack(
    location: CreatePackLocation,
    profile_path: String,
) -> crate::Result<String> {
    // Get file from description
    let create_pack: CreatePack = match location {
        CreatePackLocation::FromVersionId {
            project_id,
            version_id,
            title,
            icon_url,
        } => {
            generate_pack_from_version_id(
                project_id,
                version_id,
                title,
                icon_url,
                profile_path.clone(),
                None,
            )
            .await?
        }
        CreatePackLocation::FromFile { path } => {
            generate_pack_from_file(path, profile_path.clone()).await?
        }
    };

    // Install pack files, and if it fails, fail safely by removing the profile
    let result = install_zipped_mrpack_files(create_pack, false).await;

    match result {
        Ok(profile) => Ok(profile),
        Err(err) => {
            let _ = crate::api::profile::remove(&profile_path).await;

            Err(err)
        }
    }
}

/// Install all pack files from a description
/// Does not remove the profile if it fails
pub async fn install_zipped_mrpack_files(
    create_pack: CreatePack,
    ignore_lock: bool,
) -> crate::Result<String> {
    let state = &State::get().await?;

    let file = create_pack.file;
    let description = create_pack.description.clone(); // make a copy for profile edit function
    let icon = create_pack.description.icon;
    let project_id = create_pack.description.project_id;
    let version_id = create_pack.description.version_id;
    let existing_loading_bar = create_pack.description.existing_loading_bar;
    let profile_path = create_pack.description.profile_path;
    let icon_exists = icon.is_some();

    let reader: Cursor<&bytes::Bytes> = Cursor::new(&file);

    // Create zip reader around file
    let mut zip_reader =
        ZipFileReader::with_tokio(reader).await.map_err(|_| {
            crate::Error::from(crate::ErrorKind::InputError(
                "Failed to read input modpack zip".to_string(),
            ))
        })?;

    // Extract index of modrinth.index.json
    let Some(manifest_idx) = zip_reader.file().entries().iter().position(|f| {
        matches!(f.filename().as_str(), Ok("modrinth.index.json"))
    }) else {
        return Err(crate::Error::from(crate::ErrorKind::InputError(
            "No pack manifest found in mrpack".to_string(),
        )));
    };

    let mut manifest = String::new();
    let mut reader = zip_reader.reader_with_entry(manifest_idx).await?;
    reader.read_to_string_checked(&mut manifest).await?;

    let pack: PackFormat = serde_json::from_str(&manifest)?;

    if &*pack.game != "minecraft" {
        return Err(crate::ErrorKind::InputError(
            "Pack does not support Minecraft".to_string(),
        )
        .into());
    }

    // Sets generated profile attributes to the pack ones (using profile::edit)
    set_profile_information(
        profile_path.clone(),
        &description,
        &pack.name,
        &pack.dependencies,
        ignore_lock,
    )
    .await?;

    let profile_path = profile_path.clone();
    let loading_bar = init_or_edit_loading(
        existing_loading_bar,
        LoadingBarType::PackDownload {
            profile_path: profile_path.clone(),
            pack_name: pack.name.clone(),
            icon,
            pack_id: project_id,
            pack_version: version_id,
        },
        100.0,
        "Downloading modpack",
    )
    .await?;

    let num_files = pack.files.len();
    loading_try_for_each_concurrent(
        futures::stream::iter(pack.files.into_iter())
            .map(Ok::<PackFile, crate::Error>),
        None,
        Some(&loading_bar),
        70.0,
        num_files,
        None,
        |project| {
            let profile_path = profile_path.clone();
            async move {
                //TODO: Future update: prompt user for optional files in a modpack
                if let Some(env) = project.env
                    && env
                        .get(&EnvType::Client)
                        .is_some_and(|x| x == &SideType::Unsupported)
                {
                    return Ok(());
                }

                let file = fetch_mirrors(
                    &project
                        .downloads
                        .iter()
                        .map(|x| &**x)
                        .collect::<Vec<&str>>(),
                    project.hashes.get(&PackFileHash::Sha1).map(|x| &**x),
                    &state.fetch_semaphore,
                    &state.pool,
                )
                .await?;

                let path = profile::get_full_path(&profile_path)
                    .await?
                    .join(project.path.as_str());

                cache_file_hash(
                    file.clone(),
                    &profile_path,
                    project.path.as_str(),
                    project.hashes.get(&PackFileHash::Sha1).map(|x| &**x),
                    ProjectType::get_from_parent_folder(&path),
                    &state.pool,
                )
                .await?;

                write(&path, &file, &state.io_semaphore).await?;

                Ok(())
            }
        },
    )
    .await?;

    emit_loading(&loading_bar, 0.0, Some("Extracting overrides"))?;

    let override_file_entries = zip_reader
        .file()
        .entries()
        .iter()
        .enumerate()
        .filter_map(|(index, file)| {
            let filename = file.filename().as_str().unwrap_or_default();
            ((filename.starts_with("overrides/")
                || filename.starts_with("client-overrides/"))
                && !filename.ends_with('/'))
            .then(|| (index, file.clone()))
        })
        .collect::<Vec<_>>();
    let override_file_entries_count = override_file_entries.len();

    for (i, (index, file)) in override_file_entries.into_iter().enumerate() {
        let relative_override_file_path =
            SafeRelativeUtf8UnixPathBuf::try_from(
                file.filename().as_str().unwrap().to_string(),
            )?;
        let relative_override_file_path = relative_override_file_path
            .strip_prefix("overrides")
            .or_else(|_| relative_override_file_path.strip_prefix("client-overrides"))
            .map_err(|_| {
                crate::Error::from(crate::ErrorKind::OtherError(
                    format!("Failed to strip override prefix from override file path: {relative_override_file_path}")
                ))
            })?;

        let mut file_bytes = vec![];
        let mut reader = zip_reader.reader_with_entry(index).await?;
        reader.read_to_end_checked(&mut file_bytes).await?;

        let file_bytes = bytes::Bytes::from(file_bytes);

        cache_file_hash(
            file_bytes.clone(),
            &profile_path,
            relative_override_file_path.as_str(),
            None,
            ProjectType::get_from_parent_folder(
                relative_override_file_path.as_str(),
            ),
            &state.pool,
        )
        .await?;

        write(
            &profile::get_full_path(&profile_path)
                .await?
                .join(relative_override_file_path.as_str()),
            &file_bytes,
            &state.io_semaphore,
        )
        .await?;

        emit_loading(
            &loading_bar,
            30.0 / override_file_entries_count as f64,
            Some(&format!(
                "Extracting override {}/{override_file_entries_count}",
                i + 1
            )),
        )?;
    }

    // If the icon doesn't exist, we expect icon.png to be a potential icon.
    // If it doesn't exist, and an override to icon.png exists, cache and use that
    let potential_icon = profile::get_full_path(&profile_path)
        .await?
        .join("icon.png");
    if !icon_exists && potential_icon.exists() {
        profile::edit_icon(&profile_path, Some(&potential_icon)).await?;
    }

    if let Some(profile_val) = profile::get(&profile_path).await? {
        crate::launcher::install_minecraft(
            &profile_val,
            Some(loading_bar),
            false,
        )
        .await?;
    }

    Ok::<String, crate::Error>(profile_path.clone())
}

#[tracing::instrument(skip(mrpack_file))]

pub async fn remove_all_related_files(
    profile_path: String,
    mrpack_file: bytes::Bytes,
) -> crate::Result<()> {
    let reader: Cursor<&bytes::Bytes> = Cursor::new(&mrpack_file);

    // Create zip reader around file
    let mut zip_reader =
        ZipFileReader::with_tokio(reader).await.map_err(|_| {
            crate::Error::from(crate::ErrorKind::InputError(
                "Failed to read input modpack zip".to_string(),
            ))
        })?;

    // Extract index of modrinth.index.json
    let Some(manifest_idx) = zip_reader.file().entries().iter().position(|f| {
        matches!(f.filename().as_str(), Ok("modrinth.index.json"))
    }) else {
        return Err(crate::Error::from(crate::ErrorKind::InputError(
            "No pack manifest found in mrpack".to_string(),
        )));
    };

    let mut manifest = String::new();

    let mut reader = zip_reader.reader_with_entry(manifest_idx).await?;
    reader.read_to_string_checked(&mut manifest).await?;

    let pack: PackFormat = serde_json::from_str(&manifest)?;

    if &*pack.game != "minecraft" {
        return Err(crate::ErrorKind::InputError(
            "Pack does not support Minecraft".to_string(),
        )
        .into());
    }

    // Set install stage to installing, and do not change it back (as files are being removed and are not being reinstalled here)
    crate::api::profile::edit(&profile_path, |prof| {
        prof.install_stage = ProfileInstallStage::PackInstalling;
        async { Ok(()) }
    })
    .await?;

    // First, remove all modrinth projects by their version hashes
    // Remove all modrinth projects by their version hashes
    // We need to do a fetch to get the project ids from Modrinth
    let state = State::get().await?;
    let all_hashes = pack
        .files
        .iter()
        .filter_map(|f| Some(f.hashes.get(&PackFileHash::Sha1)?.clone()))
        .collect::<Vec<_>>();

    // First, get project info by hash
    let file_infos = CachedEntry::get_file_many(
        &all_hashes.iter().map(|x| &**x).collect::<Vec<_>>(),
        None,
        &state.pool,
        &state.api_semaphore,
    )
    .await?;

    let to_remove = file_infos
        .into_iter()
        .map(|p| p.project_id)
        .collect::<Vec<_>>();

    let profile = profile::get(&profile_path).await?.ok_or_else(|| {
        crate::ErrorKind::UnmanagedProfileError(profile_path.to_string())
    })?;
    let profile_full_path = profile::get_full_path(&profile_path).await?;

    for (file_path, project) in profile
        .get_projects(
            Some(CacheBehaviour::MustRevalidate),
            &state.pool,
            &state.api_semaphore,
        )
        .await?
    {
        if let Some(metadata) = &project.metadata
            && to_remove.contains(&metadata.project_id)
        {
            match io::remove_file(profile_full_path.join(file_path)).await {
                Ok(_) => (),
                Err(err) if err.kind() == ErrorKind::NotFound => (),
                Err(err) => return Err(err.into()),
            }
        }
    }

    // Iterate over all Modrinth project file paths in the json, and remove them
    // (There should be few, but this removes any files the .mrpack intended as Modrinth projects but were unrecognized)
    for file in pack.files {
        match io::remove_file(profile_full_path.join(file.path.as_str())).await
        {
            Ok(_) => (),
            Err(err) if err.kind() == ErrorKind::NotFound => (),
            Err(err) => return Err(err.into()),
        }
    }

    // Iterate over each 'overrides' file and remove it
    let override_file_entries =
        zip_reader.file().entries().iter().filter(|file| {
            let filename = file.filename().as_str().unwrap_or_default();
            (filename.starts_with("overrides/")
                || filename.starts_with("client-overrides/"))
                && !filename.ends_with('/')
        });

    for file in override_file_entries {
        let relative_override_file_path =
            SafeRelativeUtf8UnixPathBuf::try_from(
                file.filename().as_str().unwrap().to_string(),
            )?;
        let relative_override_file_path = relative_override_file_path
            .strip_prefix("overrides")
            .or_else(|_| relative_override_file_path.strip_prefix("client-overrides"))
            .map_err(|_| {
                crate::Error::from(crate::ErrorKind::OtherError(
                    format!("Failed to strip override prefix from override file path: {relative_override_file_path}")
                ))
            })?;

        // Remove this file if a corresponding one exists in the filesystem
        match io::remove_file(
            profile::get_full_path(&profile_path)
                .await?
                .join(relative_override_file_path.as_str()),
        )
        .await
        {
            Ok(_) => (),
            Err(err) if err.kind() == ErrorKind::NotFound => (),
            Err(err) => return Err(err.into()),
        }
    }

    Ok(())
}