use anyhow::{Error};
use lazy_static::lazy_static;
use std::collections::HashMap;

use proxmox_schema::{Schema, ApiType};
use proxmox_section_config::{SectionConfig, SectionConfigData, SectionConfigPlugin};

use pbs_api_types::{TapeBackupJobConfig, JOB_ID_SCHEMA};

use crate::{open_backup_lockfile, replace_backup_config, BackupLockGuard};

lazy_static! {
    pub static ref CONFIG: SectionConfig = init();
}

fn init() -> SectionConfig {
    let obj_schema = match TapeBackupJobConfig::API_SCHEMA {
        Schema::AllOf(ref allof_schema) => allof_schema,
        _ => unreachable!(),
    };

    let plugin = SectionConfigPlugin::new("backup".to_string(), Some(String::from("id")), obj_schema);
    let mut config = SectionConfig::new(&JOB_ID_SCHEMA);
    config.register_plugin(plugin);

    config
}

pub const TAPE_JOB_CFG_FILENAME: &str = "/etc/proxmox-backup/tape-job.cfg";
pub const TAPE_JOB_CFG_LOCKFILE: &str = "/etc/proxmox-backup/.tape-job.lck";

/// Get exclusive lock
pub fn lock() -> Result<BackupLockGuard, Error> {
    open_backup_lockfile( TAPE_JOB_CFG_LOCKFILE, None, true)
}

pub fn config() -> Result<(SectionConfigData, [u8;32]), Error> {

    let content = proxmox_sys::fs::file_read_optional_string(TAPE_JOB_CFG_FILENAME)?
        .unwrap_or_else(|| "".to_string());

    let digest = openssl::sha::sha256(content.as_bytes());
    let data = CONFIG.parse(TAPE_JOB_CFG_FILENAME, &content)?;
    Ok((data, digest))
}

pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
    let raw = CONFIG.write(TAPE_JOB_CFG_FILENAME, &config)?;
    replace_backup_config(TAPE_JOB_CFG_FILENAME, raw.as_bytes())
}

// shell completion helper

/// List all tape job IDs
pub fn complete_tape_job_id(_arg: &str, _param: &HashMap<String, String>) -> Vec<String> {
    match config() {
        Ok((data, _digest)) => data.sections.iter().map(|(id, _)| id.to_string()).collect(),
        Err(_) => return vec![],
    }
}