//! Backup metadata, creation, verification, and restore HTTP handlers.

use crate::auth::middleware::AuthenticatedAdmin;
use crate::backup::BackupService;
use crate::error::{ApiError, ApiResult};
use crate::routes::auth::GenericSuccess;
use crate::state::AppState;
use axum::body::Body;
use axum::extract::{Path, State};
use axum::http::HeaderMap;
use axum::http::header::{CONTENT_DISPOSITION, CONTENT_TYPE};
use axum::response::{IntoResponse, Response};
use axum::{Extension, Json};
use chrono::Utc;
use nx9_wg_core::types::backup::BackupMeta;
use serde::Deserialize;
use std::path::PathBuf;
use uuid::Uuid;

#[derive(Debug, Deserialize)]
pub struct CreateBackupRecordRequest {
    pub filename: String,
    pub size_bytes: i64,
    pub checksum: String,
    pub schema_version: String,
    pub encrypted: Option<bool>,
    pub description: Option<String>,
}

#[derive(Debug, Deserialize)]
pub struct TriggerBackupRequest {
    pub description: Option<String>,
}

/// GET /api/v1/backups
pub async fn list_backups_handler(
    State(state): State<AppState>,
) -> ApiResult<Json<Vec<BackupMeta>>> {
    let list = state.store.list_backups().await?;
    Ok(Json(list))
}

/// POST /api/v1/backups
pub async fn create_backup_record_handler(
    State(state): State<AppState>,
    Json(payload): Json<CreateBackupRecordRequest>,
) -> ApiResult<Json<BackupMeta>> {
    let now = Utc::now().naive_utc();
    let meta = BackupMeta {
        id: Uuid::new_v4(),
        filename: payload.filename,
        size_bytes: payload.size_bytes,
        checksum: payload.checksum,
        schema_version: payload.schema_version,
        encrypted: payload.encrypted.unwrap_or(false),
        description: payload.description,
        created_at: now,
    };

    state.store.create_backup_meta(&meta).await?;
    Ok(Json(meta))
}

/// POST /api/v1/backups/create
pub async fn trigger_backup_handler(
    State(state): State<AppState>,
    Extension(admin): Extension<AuthenticatedAdmin>,
    Json(payload): Json<TriggerBackupRequest>,
) -> ApiResult<Json<BackupMeta>> {
    let backup_dir = PathBuf::from("backups");
    let (meta, _path) = BackupService::create_backup(
        &state.store,
        &backup_dir,
        payload.description.as_deref(),
        &admin.username,
        None,
    )
    .await?;

    Ok(Json(meta))
}

/// GET /api/v1/backups/{id}
pub async fn get_backup_handler(
    State(state): State<AppState>,
    Path(id): Path<Uuid>,
) -> ApiResult<Json<BackupMeta>> {
    let meta = state
        .store
        .get_backup_meta(id)
        .await?
        .ok_or_else(|| ApiError::NotFound(format!("Backup record '{id}' not found")))?;
    Ok(Json(meta))
}

/// GET /api/v1/backups/{id}/download
pub async fn download_backup_handler(
    State(state): State<AppState>,
    Path(id): Path<Uuid>,
) -> ApiResult<Response> {
    let meta = state
        .store
        .get_backup_meta(id)
        .await?
        .ok_or_else(|| ApiError::NotFound(format!("Backup record '{id}' not found")))?;

    let backup_dir = PathBuf::from("backups");
    let file_path = backup_dir.join(&meta.filename);

    if !file_path.exists() {
        return Err(ApiError::NotFound(format!(
            "Backup archive file '{}' not found on disk",
            meta.filename
        )));
    }

    let bytes = std::fs::read(&file_path)
        .map_err(|e| ApiError::Internal(format!("Failed to read backup file for download: {e}")))?;

    let mut headers = HeaderMap::new();
    headers.insert(CONTENT_TYPE, "application/octet-stream".parse().unwrap());
    headers.insert(
        CONTENT_DISPOSITION,
        format!("attachment; filename=\"{}\"", meta.filename)
            .parse()
            .unwrap(),
    );

    Ok((headers, Body::from(bytes)).into_response())
}

/// DELETE /api/v1/backups/{id}
pub async fn delete_backup_handler(
    State(state): State<AppState>,
    Path(id): Path<Uuid>,
) -> ApiResult<Json<GenericSuccess>> {
    let meta = state.store.get_backup_meta(id).await?;
    if let Some(m) = meta {
        let backup_dir = PathBuf::from("backups");
        let file_path = backup_dir.join(&m.filename);
        let _ = std::fs::remove_file(file_path);
    }

    state.store.delete_backup_meta(id).await?;
    Ok(Json(GenericSuccess {
        success: true,
        message: format!("Backup record '{id}' deleted"),
    }))
}

/// POST /api/v1/backups/{id}/restore
pub async fn restore_backup_handler(
    State(state): State<AppState>,
    Extension(admin): Extension<AuthenticatedAdmin>,
    Path(id): Path<Uuid>,
) -> ApiResult<Json<GenericSuccess>> {
    let meta = state
        .store
        .get_backup_meta(id)
        .await?
        .ok_or_else(|| ApiError::NotFound(format!("Backup record '{id}' not found")))?;

    let backup_dir = PathBuf::from("backups");
    let file_path = backup_dir.join(&meta.filename);
    let active_db = PathBuf::from("nx9-wg.db");
    let safety_dir = backup_dir.join("safety");

    BackupService::restore_backup(
        &state.store,
        &file_path,
        &active_db,
        &safety_dir,
        &admin.username,
        None,
    )
    .await?;

    Ok(Json(GenericSuccess {
        success: true,
        message: format!(
            "Database successfully restored from backup '{}'",
            meta.filename
        ),
    }))
}