use std::collections::HashSet;

use serde::{Deserialize, Serialize};
use structopt::StructOpt;

use garage_util::data::Uuid;
use garage_util::error::Error;

use garage_rpc::ring::*;
use garage_rpc::system::*;
use garage_rpc::*;

use garage_model::bucket_table::*;
use garage_model::key_table::*;

use crate::admin_rpc::*;

#[derive(StructOpt, Debug)]
pub enum Command {
	/// Run Garage server
	#[structopt(name = "server")]
	Server,

	/// Print identifier (public key) of this garage node.
	/// Generates a new keypair if necessary.
	#[structopt(name = "node-id")]
	NodeId(NodeIdOpt),

	/// Get network status
	#[structopt(name = "status")]
	Status,

	/// Garage node operations
	#[structopt(name = "node")]
	Node(NodeOperation),

	/// Bucket operations
	#[structopt(name = "bucket")]
	Bucket(BucketOperation),

	/// Key operations
	#[structopt(name = "key")]
	Key(KeyOperation),

	/// Start repair of node data
	#[structopt(name = "repair")]
	Repair(RepairOpt),

	/// Gather node statistics
	#[structopt(name = "stats")]
	Stats(StatsOpt),
}

#[derive(StructOpt, Debug)]
pub enum NodeOperation {
	/// Connect to Garage node that is currently isolated from the system
	#[structopt(name = "connect")]
	Connect(ConnectNodeOpt),

	/// Configure Garage node
	#[structopt(name = "configure")]
	Configure(ConfigureNodeOpt),

	/// Remove Garage node from cluster
	#[structopt(name = "remove")]
	Remove(RemoveNodeOpt),
}

#[derive(StructOpt, Debug)]
pub struct NodeIdOpt {
	/// Do not print usage instructions to stderr
	#[structopt(short = "q", long = "quiet")]
	pub(crate) quiet: bool,
}

#[derive(StructOpt, Debug)]
pub struct ConnectNodeOpt {
	/// Node public key and address, in the format:
	/// `<public key hexadecimal>@<ip or hostname>:<port>`
	node: String,
}

#[derive(StructOpt, Debug)]
pub struct ConfigureNodeOpt {
	/// Node to configure (prefix of hexadecimal node id)
	node_id: String,

	/// Location (zone or datacenter) of the node
	#[structopt(short = "z", long = "zone")]
	zone: Option<String>,

	/// Capacity (in relative terms, use 1 to represent your smallest server)
	#[structopt(short = "c", long = "capacity")]
	capacity: Option<u32>,

	/// Gateway-only node
	#[structopt(short = "g", long = "gateway")]
	gateway: bool,

	/// Optional node tag
	#[structopt(short = "t", long = "tag")]
	tag: Option<String>,

	/// Replaced node(s): list of node IDs that will be removed from the current cluster
	#[structopt(long = "replace")]
	replace: Vec<String>,
}

#[derive(StructOpt, Debug)]
pub struct RemoveNodeOpt {
	/// Node to configure (prefix of hexadecimal node id)
	node_id: String,

	/// If this flag is not given, the node won't be removed
	#[structopt(long = "yes")]
	yes: bool,
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub enum BucketOperation {
	/// List buckets
	#[structopt(name = "list")]
	List,

	/// Get bucket info
	#[structopt(name = "info")]
	Info(BucketOpt),

	/// Create bucket
	#[structopt(name = "create")]
	Create(BucketOpt),

	/// Delete bucket
	#[structopt(name = "delete")]
	Delete(DeleteBucketOpt),

	/// Allow key to read or write to bucket
	#[structopt(name = "allow")]
	Allow(PermBucketOpt),

	/// Deny key from reading or writing to bucket
	#[structopt(name = "deny")]
	Deny(PermBucketOpt),

	/// Expose as website or not
	#[structopt(name = "website")]
	Website(WebsiteOpt),
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub struct WebsiteOpt {
	/// Create
	#[structopt(long = "allow")]
	pub allow: bool,

	/// Delete
	#[structopt(long = "deny")]
	pub deny: bool,

	/// Bucket name
	pub bucket: String,
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub struct BucketOpt {
	/// Bucket name
	pub name: String,
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub struct DeleteBucketOpt {
	/// Bucket name
	pub name: String,

	/// If this flag is not given, the bucket won't be deleted
	#[structopt(long = "yes")]
	pub yes: bool,
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub struct PermBucketOpt {
	/// Access key name or ID
	#[structopt(long = "key")]
	pub key_pattern: String,

	/// Allow/deny read operations
	#[structopt(long = "read")]
	pub read: bool,

	/// Allow/deny write operations
	#[structopt(long = "write")]
	pub write: bool,

	/// Bucket name
	pub bucket: String,
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub enum KeyOperation {
	/// List keys
	#[structopt(name = "list")]
	List,

	/// Get key info
	#[structopt(name = "info")]
	Info(KeyOpt),

	/// Create new key
	#[structopt(name = "new")]
	New(KeyNewOpt),

	/// Rename key
	#[structopt(name = "rename")]
	Rename(KeyRenameOpt),

	/// Delete key
	#[structopt(name = "delete")]
	Delete(KeyDeleteOpt),

	/// Import key
	#[structopt(name = "import")]
	Import(KeyImportOpt),
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub struct KeyOpt {
	/// ID or name of the key
	pub key_pattern: String,
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub struct KeyNewOpt {
	/// Name of the key
	#[structopt(long = "name", default_value = "Unnamed key")]
	pub name: String,
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub struct KeyRenameOpt {
	/// ID or name of the key
	pub key_pattern: String,

	/// New name of the key
	pub new_name: String,
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub struct KeyDeleteOpt {
	/// ID or name of the key
	pub key_pattern: String,

	/// Confirm deletion
	#[structopt(long = "yes")]
	pub yes: bool,
}

#[derive(Serialize, Deserialize, StructOpt, Debug)]
pub struct KeyImportOpt {
	/// Access key ID
	pub key_id: String,

	/// Secret access key
	pub secret_key: String,

	/// Key name
	#[structopt(short = "n", default_value = "Imported key")]
	pub name: String,
}

#[derive(Serialize, Deserialize, StructOpt, Debug, Clone)]
pub struct RepairOpt {
	/// Launch repair operation on all nodes
	#[structopt(short = "a", long = "all-nodes")]
	pub all_nodes: bool,

	/// Confirm the launch of the repair operation
	#[structopt(long = "yes")]
	pub yes: bool,

	#[structopt(subcommand)]
	pub what: Option<RepairWhat>,
}

#[derive(Serialize, Deserialize, StructOpt, Debug, Eq, PartialEq, Clone)]
pub enum RepairWhat {
	/// Only do a full sync of metadata tables
	#[structopt(name = "tables")]
	Tables,
	/// Only repair (resync/rebalance) the set of stored blocks
	#[structopt(name = "blocks")]
	Blocks,
	/// Only redo the propagation of object deletions to the version table (slow)
	#[structopt(name = "versions")]
	Versions,
	/// Only redo the propagation of version deletions to the block ref table (extremely slow)
	#[structopt(name = "block_refs")]
	BlockRefs,
}

#[derive(Serialize, Deserialize, StructOpt, Debug, Clone)]
pub struct StatsOpt {
	/// Gather statistics from all nodes
	#[structopt(short = "a", long = "all-nodes")]
	pub all_nodes: bool,

	/// Gather detailed statistics (this can be long)
	#[structopt(short = "d", long = "detailed")]
	pub detailed: bool,
}

pub async fn cli_cmd(
	cmd: Command,
	system_rpc_endpoint: &Endpoint<SystemRpc, ()>,
	admin_rpc_endpoint: &Endpoint<AdminRpc, ()>,
	rpc_host: NodeID,
) -> Result<(), Error> {
	match cmd {
		Command::Status => cmd_status(system_rpc_endpoint, rpc_host).await,
		Command::Node(NodeOperation::Connect(connect_opt)) => {
			cmd_connect(system_rpc_endpoint, rpc_host, connect_opt).await
		}
		Command::Node(NodeOperation::Configure(configure_opt)) => {
			cmd_configure(system_rpc_endpoint, rpc_host, configure_opt).await
		}
		Command::Node(NodeOperation::Remove(remove_opt)) => {
			cmd_remove(system_rpc_endpoint, rpc_host, remove_opt).await
		}
		Command::Bucket(bo) => {
			cmd_admin(admin_rpc_endpoint, rpc_host, AdminRpc::BucketOperation(bo)).await
		}
		Command::Key(ko) => {
			cmd_admin(admin_rpc_endpoint, rpc_host, AdminRpc::KeyOperation(ko)).await
		}
		Command::Repair(ro) => {
			cmd_admin(admin_rpc_endpoint, rpc_host, AdminRpc::LaunchRepair(ro)).await
		}
		Command::Stats(so) => cmd_admin(admin_rpc_endpoint, rpc_host, AdminRpc::Stats(so)).await,
		_ => unreachable!(),
	}
}

pub async fn cmd_status(rpc_cli: &Endpoint<SystemRpc, ()>, rpc_host: NodeID) -> Result<(), Error> {
	let status = match rpc_cli
		.call(&rpc_host, &SystemRpc::GetKnownNodes, PRIO_NORMAL)
		.await??
	{
		SystemRpc::ReturnKnownNodes(nodes) => nodes,
		resp => return Err(Error::Message(format!("Invalid RPC response: {:?}", resp))),
	};
	let config = match rpc_cli
		.call(&rpc_host, &SystemRpc::PullConfig, PRIO_NORMAL)
		.await??
	{
		SystemRpc::AdvertiseConfig(cfg) => cfg,
		resp => return Err(Error::Message(format!("Invalid RPC response: {:?}", resp))),
	};

	println!("==== HEALTHY NODES ====");
	let mut healthy_nodes = vec!["ID\tHostname\tAddress\tTag\tZone\tCapacity".to_string()];
	for adv in status.iter().filter(|adv| adv.is_up) {
		if let Some(cfg) = config.members.get(&adv.id) {
			healthy_nodes.push(format!(
				"{id:?}\t{host}\t{addr}\t[{tag}]\t{zone}\t{capacity}",
				id = adv.id,
				host = adv.status.hostname,
				addr = adv.addr,
				tag = cfg.tag,
				zone = cfg.zone,
				capacity = cfg.capacity_string(),
			));
		} else {
			healthy_nodes.push(format!(
				"{id:?}\t{h}\t{addr}\tNO ROLE ASSIGNED",
				id = adv.id,
				h = adv.status.hostname,
				addr = adv.addr,
			));
		}
	}
	format_table(healthy_nodes);

	let status_keys = status.iter().map(|adv| adv.id).collect::<HashSet<_>>();
	let failure_case_1 = status.iter().any(|adv| !adv.is_up);
	let failure_case_2 = config
		.members
		.iter()
		.any(|(id, _)| !status_keys.contains(id));
	if failure_case_1 || failure_case_2 {
		println!("\n==== FAILED NODES ====");
		let mut failed_nodes =
			vec!["ID\tHostname\tAddress\tTag\tZone\tCapacity\tLast seen".to_string()];
		for adv in status.iter().filter(|adv| !adv.is_up) {
			if let Some(cfg) = config.members.get(&adv.id) {
				failed_nodes.push(format!(
					"{id:?}\t{host}\t{addr}\t[{tag}]\t{zone}\t{capacity}\t{last_seen}s ago",
					id = adv.id,
					host = adv.status.hostname,
					addr = adv.addr,
					tag = cfg.tag,
					zone = cfg.zone,
					capacity = cfg.capacity_string(),
					last_seen = "FIXME", // FIXME was (now_msec() - adv.last_seen) / 1000,
				));
			}
		}
		for (id, cfg) in config.members.iter() {
			if !status.iter().any(|adv| adv.id == *id) {
				failed_nodes.push(format!(
					"{id:?}\t??\t??\t[{tag}]\t{zone}\t{capacity}\tnever seen",
					id = id,
					tag = cfg.tag,
					zone = cfg.zone,
					capacity = cfg.capacity_string(),
				));
			}
		}
		format_table(failed_nodes);
	}

	Ok(())
}

pub async fn cmd_connect(
	rpc_cli: &Endpoint<SystemRpc, ()>,
	rpc_host: NodeID,
	args: ConnectNodeOpt,
) -> Result<(), Error> {
	match rpc_cli
		.call(&rpc_host, &SystemRpc::Connect(args.node), PRIO_NORMAL)
		.await??
	{
		SystemRpc::Ok => {
			println!("Success.");
			Ok(())
		}
		r => Err(Error::BadRpc(format!("Unexpected response: {:?}", r))),
	}
}

pub async fn cmd_configure(
	rpc_cli: &Endpoint<SystemRpc, ()>,
	rpc_host: NodeID,
	args: ConfigureNodeOpt,
) -> Result<(), Error> {
	let status = match rpc_cli
		.call(&rpc_host, &SystemRpc::GetKnownNodes, PRIO_NORMAL)
		.await??
	{
		SystemRpc::ReturnKnownNodes(nodes) => nodes,
		resp => return Err(Error::Message(format!("Invalid RPC response: {:?}", resp))),
	};

	let added_node = find_matching_node(status.iter().map(|adv| adv.id), &args.node_id)?;

	let mut config = match rpc_cli
		.call(&rpc_host, &SystemRpc::PullConfig, PRIO_NORMAL)
		.await??
	{
		SystemRpc::AdvertiseConfig(cfg) => cfg,
		resp => return Err(Error::Message(format!("Invalid RPC response: {:?}", resp))),
	};

	for replaced in args.replace.iter() {
		let replaced_node = find_matching_node(config.members.keys().cloned(), replaced)?;
		if config.members.remove(&replaced_node).is_none() {
			return Err(Error::Message(format!(
				"Cannot replace node {:?} as it is not in current configuration",
				replaced_node
			)));
		}
	}

	if args.capacity.is_some() && args.gateway {
		return Err(Error::Message(
				"-c and -g are mutually exclusive, please configure node either with c>0 to act as a storage node or with -g to act as a gateway node".into()));
	}
	if args.capacity == Some(0) {
		return Err(Error::Message("Invalid capacity value: 0".into()));
	}

	let new_entry = match config.members.get(&added_node) {
		None => {
			let capacity = match args.capacity {
				Some(c) => Some(c),
				None if args.gateway => None,
				_ => return Err(Error::Message(
						"Please specify a capacity with the -c flag, or set node explicitly as gateway with -g".into())),
			};
			NetworkConfigEntry {
				zone: args.zone.expect("Please specifiy a zone with the -z flag"),
				capacity,
				tag: args.tag.unwrap_or_default(),
			}
		}
		Some(old) => {
			let capacity = match args.capacity {
				Some(c) => Some(c),
				None if args.gateway => None,
				_ => old.capacity,
			};
			NetworkConfigEntry {
				zone: args.zone.unwrap_or_else(|| old.zone.to_string()),
				capacity,
				tag: args.tag.unwrap_or_else(|| old.tag.to_string()),
			}
		}
	};

	config.members.insert(added_node, new_entry);
	config.version += 1;

	rpc_cli
		.call(&rpc_host, &SystemRpc::AdvertiseConfig(config), PRIO_NORMAL)
		.await??;
	Ok(())
}

pub async fn cmd_remove(
	rpc_cli: &Endpoint<SystemRpc, ()>,
	rpc_host: NodeID,
	args: RemoveNodeOpt,
) -> Result<(), Error> {
	let mut config = match rpc_cli
		.call(&rpc_host, &SystemRpc::PullConfig, PRIO_NORMAL)
		.await??
	{
		SystemRpc::AdvertiseConfig(cfg) => cfg,
		resp => return Err(Error::Message(format!("Invalid RPC response: {:?}", resp))),
	};

	let deleted_node = find_matching_node(config.members.keys().cloned(), &args.node_id)?;

	if !args.yes {
		return Err(Error::Message(format!(
			"Add the flag --yes to really remove {:?} from the cluster",
			deleted_node
		)));
	}

	config.members.remove(&deleted_node);
	config.version += 1;

	rpc_cli
		.call(&rpc_host, &SystemRpc::AdvertiseConfig(config), PRIO_NORMAL)
		.await??;
	Ok(())
}

pub async fn cmd_admin(
	rpc_cli: &Endpoint<AdminRpc, ()>,
	rpc_host: NodeID,
	args: AdminRpc,
) -> Result<(), Error> {
	match rpc_cli.call(&rpc_host, &args, PRIO_NORMAL).await?? {
		AdminRpc::Ok(msg) => {
			println!("{}", msg);
		}
		AdminRpc::BucketList(bl) => {
			println!("List of buckets:");
			for bucket in bl {
				println!("{}", bucket);
			}
		}
		AdminRpc::BucketInfo(bucket) => {
			print_bucket_info(&bucket);
		}
		AdminRpc::KeyList(kl) => {
			println!("List of keys:");
			for key in kl {
				println!("{}\t{}", key.0, key.1);
			}
		}
		AdminRpc::KeyInfo(key) => {
			print_key_info(&key);
		}
		r => {
			error!("Unexpected response: {:?}", r);
		}
	}
	Ok(())
}

// --- Utility functions ----

fn print_key_info(key: &Key) {
	println!("Key name: {}", key.name.get());
	println!("Key ID: {}", key.key_id);
	println!("Secret key: {}", key.secret_key);
	if key.deleted.get() {
		println!("Key is deleted.");
	} else {
		println!("Authorized buckets:");
		for (b, _, perm) in key.authorized_buckets.items().iter() {
			println!("- {} R:{} W:{}", b, perm.allow_read, perm.allow_write);
		}
	}
}

fn print_bucket_info(bucket: &Bucket) {
	println!("Bucket name: {}", bucket.name);
	match bucket.state.get() {
		BucketState::Deleted => println!("Bucket is deleted."),
		BucketState::Present(p) => {
			println!("Authorized keys:");
			for (k, _, perm) in p.authorized_keys.items().iter() {
				println!("- {} R:{} W:{}", k, perm.allow_read, perm.allow_write);
			}
			println!("Website access: {}", p.website.get());
		}
	};
}

fn format_table(data: Vec<String>) {
	let data = data
		.iter()
		.map(|s| s.split('\t').collect::<Vec<_>>())
		.collect::<Vec<_>>();

	let columns = data.iter().map(|row| row.len()).fold(0, std::cmp::max);
	let mut column_size = vec![0; columns];

	let mut out = String::new();

	for row in data.iter() {
		for (i, col) in row.iter().enumerate() {
			column_size[i] = std::cmp::max(column_size[i], col.chars().count());
		}
	}

	for row in data.iter() {
		for (col, col_len) in row[..row.len() - 1].iter().zip(column_size.iter()) {
			out.push_str(col);
			(0..col_len - col.chars().count() + 2).for_each(|_| out.push(' '));
		}
		out.push_str(&row[row.len() - 1]);
		out.push('\n');
	}

	print!("{}", out);
}

pub fn find_matching_node(
	cand: impl std::iter::Iterator<Item = Uuid>,
	pattern: &str,
) -> Result<Uuid, Error> {
	let mut candidates = vec![];
	for c in cand {
		if hex::encode(&c).starts_with(&pattern) {
			candidates.push(c);
		}
	}
	if candidates.len() != 1 {
		Err(Error::Message(format!(
			"{} nodes match '{}'",
			candidates.len(),
			pattern,
		)))
	} else {
		Ok(candidates[0])
	}
}