use anyhow::{bail, format_err, Error};
use serde_json::Value;

use proxmox_router::{cli::*, ApiHandler, RpcEnvironment};
use proxmox_schema::{api, param_bail};
use proxmox_sys::linux::tty;

use pbs_api_types::{
    Fingerprint, Kdf, DRIVE_NAME_SCHEMA, PASSWORD_HINT_SCHEMA,
    TAPE_ENCRYPTION_KEY_FINGERPRINT_SCHEMA,
};

use pbs_config::key_config::KeyConfig;
use pbs_config::tape_encryption_keys::{complete_key_fingerprint, load_key_configs};
use pbs_datastore::paperkey::{generate_paper_key, PaperkeyFormat};

use proxmox_backup::api2;

pub fn encryption_key_commands() -> CommandLineInterface {
    let cmd_def = CliCommandMap::new()
        .insert("list", CliCommand::new(&API_METHOD_LIST_KEYS))
        .insert("create", CliCommand::new(&API_METHOD_CREATE_KEY))
        .insert(
            "change-passphrase",
            CliCommand::new(&API_METHOD_CHANGE_PASSPHRASE)
                .arg_param(&["fingerprint"])
                .completion_cb("fingerprint", complete_key_fingerprint),
        )
        .insert(
            "show",
            CliCommand::new(&API_METHOD_SHOW_KEY)
                .arg_param(&["fingerprint"])
                .completion_cb("fingerprint", complete_key_fingerprint),
        )
        .insert(
            "paperkey",
            CliCommand::new(&API_METHOD_PAPER_KEY)
                .arg_param(&["fingerprint"])
                .completion_cb("fingerprint", complete_key_fingerprint),
        )
        .insert("restore", CliCommand::new(&API_METHOD_RESTORE_KEY))
        .insert(
            "remove",
            CliCommand::new(&api2::config::tape_encryption_keys::API_METHOD_DELETE_KEY)
                .arg_param(&["fingerprint"])
                .completion_cb("fingerprint", complete_key_fingerprint),
        );

    cmd_def.into()
}

#[api(
    input: {
        properties: {
            fingerprint: {
                schema: TAPE_ENCRYPTION_KEY_FINGERPRINT_SCHEMA,
            },
            subject: {
                description: "Include the specified subject as title text.",
                optional: true,
            },
            "output-format": {
                type: PaperkeyFormat,
                optional: true,
            },
        },
    },
)]
/// Generate a printable, human readable text file containing the encryption key.
///
/// This also includes a scanable QR code for fast key restore.
fn paper_key(
    fingerprint: Fingerprint,
    subject: Option<String>,
    output_format: Option<PaperkeyFormat>,
) -> Result<(), Error> {
    let (config_map, _digest) = load_key_configs()?;

    let key_config = match config_map.get(&fingerprint) {
        Some(key_config) => key_config,
        None => bail!("tape encryption key '{}' does not exist.", fingerprint),
    };

    let data: String = serde_json::to_string_pretty(&key_config)?;

    generate_paper_key(std::io::stdout(), &data, subject, output_format)
}

#[api(
    input: {
        properties: {
            fingerprint: {
                schema: TAPE_ENCRYPTION_KEY_FINGERPRINT_SCHEMA,
            },
            "output-format": {
                schema: OUTPUT_FORMAT,
                optional: true,
            },
        },
    },
)]
/// Print the encryption key's metadata.
fn show_key(param: Value, rpcenv: &mut dyn RpcEnvironment) -> Result<(), Error> {
    let output_format = get_output_format(&param);

    let info = &api2::config::tape_encryption_keys::API_METHOD_READ_KEY;
    let mut data = match info.handler {
        ApiHandler::Sync(handler) => (handler)(param, info, rpcenv)?,
        _ => unreachable!(),
    };

    let options = proxmox_router::cli::default_table_format_options()
        .column(ColumnConfig::new("kdf"))
        .column(ColumnConfig::new("created").renderer(pbs_tools::format::render_epoch))
        .column(ColumnConfig::new("modified").renderer(pbs_tools::format::render_epoch))
        .column(ColumnConfig::new("fingerprint"))
        .column(ColumnConfig::new("hint"));

    format_and_print_result_full(&mut data, &info.returns, &output_format, &options);

    Ok(())
}

#[api(
    input: {
        properties: {
            kdf: {
                type: Kdf,
                optional: true,
            },
            fingerprint: {
                schema: TAPE_ENCRYPTION_KEY_FINGERPRINT_SCHEMA,
            },
            hint: {
                schema: PASSWORD_HINT_SCHEMA,
            },
            force: {
                optional: true,
                type: bool,
                description: "Reset the passphrase for a tape key, without asking for the old one.",
                default: false,
            },
        },
    },
)]
/// Change the encryption key's password.
fn change_passphrase(
    force: bool,
    mut param: Value,
    rpcenv: &mut dyn RpcEnvironment,
) -> Result<(), Error> {
    if !tty::stdin_isatty() {
        bail!("unable to change passphrase - no tty");
    }

    if force {
        param["force"] = serde_json::Value::Bool(true);
    } else {
        let password = tty::read_password("Current Tape Encryption Key Password: ")?;
        param["password"] = String::from_utf8(password)?.into();
    }

    let new_password = tty::read_and_verify_password("New Tape Encryption Key Password: ")?;

    param["new-password"] = String::from_utf8(new_password)?.into();

    let info = &api2::config::tape_encryption_keys::API_METHOD_CHANGE_PASSPHRASE;
    match info.handler {
        ApiHandler::Sync(handler) => (handler)(param, info, rpcenv)?,
        _ => unreachable!(),
    };

    Ok(())
}

#[api(
    input: {
        properties: {
            drive: {
                schema: DRIVE_NAME_SCHEMA,
                optional: true,
            },
            key: {
                description: "Import key from json string or an exported paperkey-format.",
                type: String,
                optional: true,
            },
            "key-file": {
                description: "Import key from a file with either json or exported paperkey-format.",
                type: String,
                optional: true,
            },
        },
    },
)]
/// Restore encryption key from tape or from a backup file/string (reads password from stdin)
async fn restore_key(
    mut param: Value,
    key: Option<String>,
    key_file: Option<String>,
    rpcenv: &mut dyn RpcEnvironment,
) -> Result<(), Error> {
    let drive_passed = param.get("drive").is_some();
    if drive_passed && (key.is_some() || key_file.is_some()) {
        bail!("cannot have both 'drive' and 'key(-file)' parameter set!");
    } else if key.is_some() && key_file.is_some() {
        bail!("cannot have both 'key' and 'key-file' parameter set!");
    } else if !drive_passed && key.is_none() && key_file.is_none() {
        bail!("one of either 'drive' or 'key' parameter must be set!");
    }
    if !tty::stdin_isatty() {
        bail!("no password input mechanism available");
    }

    if drive_passed {
        let (config, _digest) = pbs_config::drive::config()?;
        match crate::extract_drive_name(&mut param, &config) {
            Ok(drive) => param["drive"] = drive.into(),
            Err(err) => param_bail!("drive", format_err!("invalid drive - {}", err)),
        }
    }

    let key = match key_file {
        Some(key_file) => Some(proxmox_sys::fs::file_read_string(key_file)?),
        None => key,
    };
    if let Some(data) = key {
        let key = if serde_json::from_str::<KeyConfig>(&data).is_ok() {
            &data
        } else {
            const BEGIN_MARKER: &str = "-----BEGIN PROXMOX BACKUP KEY-----";
            const END_MARKER: &str = "-----END PROXMOX BACKUP KEY-----";
            // exported paperkey-file
            let start = data
                .find(BEGIN_MARKER)
                .ok_or_else(|| format_err!("cannot find key start marker"))?
                + BEGIN_MARKER.len();
            let data_remain = &data[start..];
            let end = data_remain
                .find(END_MARKER)
                .ok_or_else(|| format_err!("cannot find key end marker below start marker"))?;
            &data_remain[..end]
        };
        println!("key to import: {}", key);
        param["key"] = key.into();
    }

    let password = tty::read_password("Tape Encryption Key Password: ")?;
    param["password"] = String::from_utf8(password)?.into();

    let info = &api2::tape::drive::API_METHOD_RESTORE_KEY;
    match info.handler {
        ApiHandler::Async(handler) => (handler)(param, info, rpcenv).await?,
        _ => unreachable!(),
    };

    Ok(())
}

#[api(
    input: {
        properties: {
            kdf: {
                type: Kdf,
                optional: true,
            },
            hint: {
                description: "Password restore hint.",
                type: String,
                min_length: 1,
                max_length: 32,
            },
        },
    },
)]
/// Create key (read password from stdin)
fn create_key(mut param: Value, rpcenv: &mut dyn RpcEnvironment) -> Result<(), Error> {
    if !tty::stdin_isatty() {
        bail!("no password input mechanism available");
    }

    let password = tty::read_and_verify_password("Tape Encryption Key Password: ")?;

    param["password"] = String::from_utf8(password)?.into();

    let info = &api2::config::tape_encryption_keys::API_METHOD_CREATE_KEY;
    let fingerprint = match info.handler {
        ApiHandler::Sync(handler) => (handler)(param, info, rpcenv)?,
        _ => unreachable!(),
    };

    println!("{}", fingerprint);

    Ok(())
}

#[api(
    input: {
        properties: {
            "output-format": {
                schema: OUTPUT_FORMAT,
                optional: true,
            },
        },
    },
)]
/// List keys
fn list_keys(param: Value, rpcenv: &mut dyn RpcEnvironment) -> Result<(), Error> {
    let output_format = get_output_format(&param);
    let info = &api2::config::tape_encryption_keys::API_METHOD_LIST_KEYS;
    let mut data = match info.handler {
        ApiHandler::Sync(handler) => (handler)(param, info, rpcenv)?,
        _ => unreachable!(),
    };

    let options = default_table_format_options()
        .column(ColumnConfig::new("fingerprint"))
        .column(ColumnConfig::new("hint"));

    format_and_print_result_full(&mut data, &info.returns, &output_format, &options);

    Ok(())
}