use crate::app_config::AppConfig;
use crate::constants;
use crate::controllers::HttpResult;
use crate::converters::finances_manager_converter::{
    FinancesManagerAccount, FinancesManagerFile, FinancesManagerMovement,
};
use crate::extractors::auth_extractor::AuthExtractor;
use crate::extractors::file_extractor::FileExtractor;
use crate::models::accounts::{Account, AccountID, AccountType};
use crate::models::files;
use crate::models::files::FileID;
use crate::models::movements::Movement;
use crate::services::accounts_service::UpdateAccountQuery;
use crate::services::movements_service::UpdateMovementQuery;
use crate::services::{accounts_service, files_service, movements_service};
use crate::utils::time_utils::{format_date, time};
use actix_files::NamedFile;
use actix_web::{HttpRequest, HttpResponse};
use serde::Serialize;
use serde::de::DeserializeOwned;
use std::collections::HashMap;
use std::fs::File;
use std::io::{Cursor, Read, Seek, Write};
use zip::write::SimpleFileOptions;
use zip::{ZipArchive, ZipWriter};

#[derive(thiserror::Error, Debug)]
pub enum BackupControllerError {
    #[error("The account with id {0:?} does not exists!")]
    NonexistentAccountId(AccountID),
    #[error("The file with id {0:?} does not exists!")]
    NonexistentFileId(FileID),
}

/// Generate export filename
fn export_filename(ext: &str) -> String {
    format!(
        "export_{}.{ext}",
        format_date(time() as i64).unwrap().replace('/', "-")
    )
}

/// Import data from a [FinancesManager](https://gitlab.com/pierre42100/cpp-financesmanager) file
pub async fn finances_manager_import(auth: AuthExtractor, file: FileExtractor) -> HttpResult {
    let file = FinancesManagerFile::parse(&String::from_utf8_lossy(&file.buff))?;

    // Create each account & push the movements independently
    for file_account in file.accounts {
        let account = accounts_service::create(
            auth.user_id(),
            &UpdateAccountQuery {
                name: file_account.name,
                r#type: AccountType::Cash,
            },
        )
        .await?;

        for file_movement in file_account.movements {
            movements_service::create(&UpdateMovementQuery {
                account_id: account.id(),
                time: file_movement.time,
                label: file_movement.label,
                file_id: None,
                amount: file_movement.amount,
                checked: false,
            })
            .await?;
        }
    }

    Ok(HttpResponse::Accepted().finish())
}

/// Export data to a [FinancesManager](https://gitlab.com/pierre42100/cpp-financesmanager) file
pub async fn finances_manager_export(auth: AuthExtractor) -> HttpResult {
    let accounts = accounts_service::get_list_user(auth.user_id()).await?;

    let mut out = FinancesManagerFile { accounts: vec![] };

    for account in accounts {
        let movements = movements_service::get_list_account(account.id()).await?;
        let mut file_account = FinancesManagerAccount {
            name: account.name,
            movements: Vec::with_capacity(movements.len()),
        };

        for movement in movements {
            file_account.movements.push(FinancesManagerMovement {
                label: movement.label,
                time: movement.time as u64,
                amount: movement.amount,
            });
        }

        out.accounts.push(file_account);
    }

    Ok(HttpResponse::Ok()
        .insert_header((
            "Content-Disposition",
            format!("attachment; filename={}", export_filename("finance")),
        ))
        .body(out.encode()))
}

/// Add JSON file to ZIP
fn zip_json<E: Serialize>(
    zip: &mut ZipWriter<File>,
    path: &str,
    content: &E,
) -> anyhow::Result<()> {
    let file_encoded = serde_json::to_string(&content)?;

    let options = SimpleFileOptions::default()
        .compression_method(zip::CompressionMethod::Deflated)
        .unix_permissions(0o750);

    zip.start_file(path, options)?;
    zip.write_all(file_encoded.as_bytes())?;
    Ok(())
}

/// Export all user data as ZIP
pub async fn zip_export(req: HttpRequest, auth: AuthExtractor) -> HttpResult {
    let dest_dir = tempfile::tempdir_in(&AppConfig::get().temp_dir)?;
    let zip_path = dest_dir.path().join("export.zip");

    let file = File::create(&zip_path)?;
    let mut zip = ZipWriter::new(file);

    // Process all JSON documents
    zip_json(
        &mut zip,
        constants::zip_export::ACCOUNTS_FILE,
        &accounts_service::get_list_user(auth.user_id()).await?,
    )?;
    zip_json(
        &mut zip,
        constants::zip_export::MOVEMENTS_FILE,
        &movements_service::get_all_movements_user(auth.user_id()).await?,
    )?;
    let files_list = files_service::get_all_files_user(auth.user_id()).await?;
    zip_json(&mut zip, constants::zip_export::FILES_FILE, &files_list)?;
    // TODO : inbox

    // Process all files
    for file in files_list {
        let buff = files_service::get_file_content(&file).await?;

        let options = SimpleFileOptions::default()
            .compression_method(zip::CompressionMethod::Deflated)
            .unix_permissions(0o750);

        zip.start_file(
            format!("{}{}", constants::zip_export::FILES_DIR, file.sha512),
            options,
        )?;
        zip.write_all(&buff)?;
    }

    // Finalize ZIP and return response
    zip.finish()?;
    let file = File::open(zip_path)?;

    let file = NamedFile::from_file(file, export_filename("zip"))?;

    Ok(file.into_response(&req))
}

/// Read JSON from archive
fn unzip_json<E: DeserializeOwned, R: Read + Seek>(
    zip: &mut ZipArchive<R>,
    path: &str,
) -> anyhow::Result<E> {
    let mut file = zip.by_name(path)?;
    let mut content = String::with_capacity(file.size() as usize);
    file.read_to_string(&mut content)?;

    Ok(serde_json::from_str(&content)?)
}

/// Replace all data with data included in ZIP file
pub async fn zip_import(auth: AuthExtractor, file: FileExtractor) -> HttpResult {
    // Parse provided files
    let zip_cursor = Cursor::new(file.buff);
    let mut zip = ZipArchive::new(zip_cursor)?;

    let new_accounts: Vec<Account> = unzip_json(&mut zip, constants::zip_export::ACCOUNTS_FILE)?;
    let new_movements: Vec<Movement> = unzip_json(&mut zip, constants::zip_export::MOVEMENTS_FILE)?;
    let new_files: Vec<files::File> = unzip_json(&mut zip, constants::zip_export::FILES_FILE)?;
    // TODO : inbox

    // Delete all data
    accounts_service::delete_all_user(auth.user_id()).await?;
    files_service::delete_all_user(auth.user_id()).await?;

    // Create the files
    let mut files_mapping = HashMap::new();
    for file in new_files {
        let mut zip_file = zip
            .by_name(&format!(
                "{}{}",
                constants::zip_export::FILES_DIR,
                file.sha512
            ))
            .map_err(|e| anyhow::anyhow!("Could not find file with hash {}: {}", file.sha512, e))?;
        let mut file_buff = Vec::with_capacity(zip_file.size() as usize);
        zip_file.read_to_end(&mut file_buff)?;
        let created_file =
            files_service::create_file_with_file_name(auth.user_id(), &file.file_name, &file_buff)
                .await?;
        files_mapping.insert(file.id(), created_file);
    }

    // Create the accounts
    let mut accounts_mapping = HashMap::new();
    for account in new_accounts {
        let created_account = accounts_service::create(
            auth.user_id(),
            &UpdateAccountQuery {
                name: account.name.to_string(),
                r#type: account.account_type(),
            },
        )
        .await?;

        if account.default_account {
            accounts_service::set_default(auth.user_id(), created_account.id()).await?;
        }

        accounts_mapping.insert(account.id(), created_account);
    }

    // Create the movements
    for movement in new_movements {
        movements_service::create(&UpdateMovementQuery {
            account_id: accounts_mapping
                .get(&movement.account_id())
                .ok_or_else(|| BackupControllerError::NonexistentAccountId(movement.account_id()))?
                .id(),
            time: movement.time as u64,
            label: movement.label.to_string(),
            file_id: movement
                .file_id()
                .map(|file_id| {
                    files_mapping
                        .get(&file_id)
                        .ok_or(BackupControllerError::NonexistentFileId(file_id))
                })
                .transpose()?
                .map(|f| f.id()),
            amount: movement.amount,
            checked: movement.checked,
        })
        .await?;
    }

    Ok(HttpResponse::Accepted().finish())
}