use std::collections::HashMap;

use anyhow::Error;
use lazy_static::lazy_static;

use proxmox_schema::*;
use proxmox_section_config::{SectionConfig, SectionConfigData, SectionConfigPlugin};

use pbs_api_types::{PruneJobConfig, JOB_ID_SCHEMA};

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

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

fn init() -> SectionConfig {
    const OBJ_SCHEMA: &AllOfSchema = PruneJobConfig::API_SCHEMA.unwrap_all_of_schema();

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

    config
}

pub const PRUNE_CFG_FILENAME: &str = "/etc/proxmox-backup/prune.cfg";
pub const PRUNE_CFG_LOCKFILE: &str = "/etc/proxmox-backup/.prune.lck";

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

pub fn config() -> Result<(SectionConfigData, [u8; 32]), Error> {
    let content = proxmox_sys::fs::file_read_optional_string(PRUNE_CFG_FILENAME)?;
    let content = content.unwrap_or_else(String::new);

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

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

// shell completion helper
pub fn complete_prune_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![],
    }
}