use std::collections::HashMap;
use std::sync::Arc;

use hyper::{body::Incoming as IncomingBody, Request, Response, StatusCode};
use serde::{Deserialize, Serialize};

use garage_util::crdt::*;
use garage_util::data::*;
use garage_util::time::*;

use garage_table::*;

use garage_model::bucket_alias_table::*;
use garage_model::bucket_table::*;
use garage_model::garage::Garage;
use garage_model::permission::*;
use garage_model::s3::mpu_table;
use garage_model::s3::object_table::*;

use crate::admin::api_server::ResBody;
use crate::admin::error::*;
use crate::admin::key::ApiBucketKeyPerm;
use crate::common_error::CommonError;
use crate::helpers::*;

pub async fn handle_list_buckets(garage: &Arc<Garage>) -> Result<Response<ResBody>, Error> {
	let buckets = garage
		.bucket_table
		.get_range(
			&EmptyKey,
			None,
			Some(DeletedFilter::NotDeleted),
			10000,
			EnumerationOrder::Forward,
		)
		.await?;

	let res = buckets
		.into_iter()
		.map(|b| {
			let state = b.state.as_option().unwrap();
			ListBucketResultItem {
				id: hex::encode(b.id),
				global_aliases: state
					.aliases
					.items()
					.iter()
					.filter(|(_, _, a)| *a)
					.map(|(n, _, _)| n.to_string())
					.collect::<Vec<_>>(),
				local_aliases: state
					.local_aliases
					.items()
					.iter()
					.filter(|(_, _, a)| *a)
					.map(|((k, n), _, _)| BucketLocalAlias {
						access_key_id: k.to_string(),
						alias: n.to_string(),
					})
					.collect::<Vec<_>>(),
			}
		})
		.collect::<Vec<_>>();

	Ok(json_ok_response(&res)?)
}

#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
struct ListBucketResultItem {
	id: String,
	global_aliases: Vec<String>,
	local_aliases: Vec<BucketLocalAlias>,
}

#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
struct BucketLocalAlias {
	access_key_id: String,
	alias: String,
}

#[derive(Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
struct ApiBucketQuotas {
	max_size: Option<u64>,
	max_objects: Option<u64>,
}

pub async fn handle_get_bucket_info(
	garage: &Arc<Garage>,
	id: Option<String>,
	global_alias: Option<String>,
) -> Result<Response<ResBody>, Error> {
	let bucket_id = match (id, global_alias) {
		(Some(id), None) => parse_bucket_id(&id)?,
		(None, Some(ga)) => garage
			.bucket_helper()
			.resolve_global_bucket_name(&ga)
			.await?
			.ok_or_else(|| HelperError::NoSuchBucket(ga.to_string()))?,
		_ => {
			return Err(Error::bad_request(
				"Either id or globalAlias must be provided (but not both)",
			));
		}
	};

	bucket_info_results(garage, bucket_id).await
}

async fn bucket_info_results(
	garage: &Arc<Garage>,
	bucket_id: Uuid,
) -> Result<Response<ResBody>, Error> {
	let bucket = garage
		.bucket_helper()
		.get_existing_bucket(bucket_id)
		.await?;

	let counters = garage
		.object_counter_table
		.table
		.get(&bucket_id, &EmptyKey)
		.await?
		.map(|x| x.filtered_values(&garage.system.cluster_layout()))
		.unwrap_or_default();

	let mpu_counters = garage
		.mpu_counter_table
		.table
		.get(&bucket_id, &EmptyKey)
		.await?
		.map(|x| x.filtered_values(&garage.system.cluster_layout()))
		.unwrap_or_default();

	let mut relevant_keys = HashMap::new();
	for (k, _) in bucket
		.state
		.as_option()
		.unwrap()
		.authorized_keys
		.items()
		.iter()
	{
		if let Some(key) = garage
			.key_table
			.get(&EmptyKey, k)
			.await?
			.filter(|k| !k.is_deleted())
		{
			if !key.state.is_deleted() {
				relevant_keys.insert(k.clone(), key);
			}
		}
	}
	for ((k, _), _, _) in bucket
		.state
		.as_option()
		.unwrap()
		.local_aliases
		.items()
		.iter()
	{
		if relevant_keys.contains_key(k) {
			continue;
		}
		if let Some(key) = garage.key_table.get(&EmptyKey, k).await? {
			if !key.state.is_deleted() {
				relevant_keys.insert(k.clone(), key);
			}
		}
	}

	let state = bucket.state.as_option().unwrap();

	let quotas = state.quotas.get();
	let res =
		GetBucketInfoResult {
			id: hex::encode(bucket.id),
			global_aliases: state
				.aliases
				.items()
				.iter()
				.filter(|(_, _, a)| *a)
				.map(|(n, _, _)| n.to_string())
				.collect::<Vec<_>>(),
			website_access: state.website_config.get().is_some(),
			website_config: state.website_config.get().clone().map(|wsc| {
				GetBucketInfoWebsiteResult {
					index_document: wsc.index_document,
					error_document: wsc.error_document,
				}
			}),
			keys: relevant_keys
				.into_values()
				.map(|key| {
					let p = key.state.as_option().unwrap();
					GetBucketInfoKey {
						access_key_id: key.key_id,
						name: p.name.get().to_string(),
						permissions: p
							.authorized_buckets
							.get(&bucket.id)
							.map(|p| ApiBucketKeyPerm {
								read: p.allow_read,
								write: p.allow_write,
								owner: p.allow_owner,
							})
							.unwrap_or_default(),
						bucket_local_aliases: p
							.local_aliases
							.items()
							.iter()
							.filter(|(_, _, b)| *b == Some(bucket.id))
							.map(|(n, _, _)| n.to_string())
							.collect::<Vec<_>>(),
					}
				})
				.collect::<Vec<_>>(),
			objects: *counters.get(OBJECTS).unwrap_or(&0),
			bytes: *counters.get(BYTES).unwrap_or(&0),
			unfinished_uploads: *counters.get(UNFINISHED_UPLOADS).unwrap_or(&0),
			unfinished_multipart_uploads: *mpu_counters.get(mpu_table::UPLOADS).unwrap_or(&0),
			unfinished_multipart_upload_parts: *mpu_counters.get(mpu_table::PARTS).unwrap_or(&0),
			unfinished_multipart_upload_bytes: *mpu_counters.get(mpu_table::BYTES).unwrap_or(&0),
			quotas: ApiBucketQuotas {
				max_size: quotas.max_size,
				max_objects: quotas.max_objects,
			},
		};

	Ok(json_ok_response(&res)?)
}

#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
struct GetBucketInfoResult {
	id: String,
	global_aliases: Vec<String>,
	website_access: bool,
	#[serde(default)]
	website_config: Option<GetBucketInfoWebsiteResult>,
	keys: Vec<GetBucketInfoKey>,
	objects: i64,
	bytes: i64,
	unfinished_uploads: i64,
	unfinished_multipart_uploads: i64,
	unfinished_multipart_upload_parts: i64,
	unfinished_multipart_upload_bytes: i64,
	quotas: ApiBucketQuotas,
}

#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
struct GetBucketInfoWebsiteResult {
	index_document: String,
	error_document: Option<String>,
}

#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
struct GetBucketInfoKey {
	access_key_id: String,
	name: String,
	permissions: ApiBucketKeyPerm,
	bucket_local_aliases: Vec<String>,
}

pub async fn handle_create_bucket(
	garage: &Arc<Garage>,
	req: Request<IncomingBody>,
) -> Result<Response<ResBody>, Error> {
	let req = parse_json_body::<CreateBucketRequest, _, Error>(req).await?;

	if let Some(ga) = &req.global_alias {
		if !is_valid_bucket_name(ga) {
			return Err(Error::bad_request(format!(
				"{}: {}",
				ga, INVALID_BUCKET_NAME_MESSAGE
			)));
		}

		if let Some(alias) = garage.bucket_alias_table.get(&EmptyKey, ga).await? {
			if alias.state.get().is_some() {
				return Err(CommonError::BucketAlreadyExists.into());
			}
		}
	}

	if let Some(la) = &req.local_alias {
		if !is_valid_bucket_name(&la.alias) {
			return Err(Error::bad_request(format!(
				"{}: {}",
				la.alias, INVALID_BUCKET_NAME_MESSAGE
			)));
		}

		let key = garage
			.key_helper()
			.get_existing_key(&la.access_key_id)
			.await?;
		let state = key.state.as_option().unwrap();
		if matches!(state.local_aliases.get(&la.alias), Some(_)) {
			return Err(Error::bad_request("Local alias already exists"));
		}
	}

	let bucket = Bucket::new();
	garage.bucket_table.insert(&bucket).await?;

	if let Some(ga) = &req.global_alias {
		garage
			.bucket_helper()
			.set_global_bucket_alias(bucket.id, ga)
			.await?;
	}

	if let Some(la) = &req.local_alias {
		garage
			.bucket_helper()
			.set_local_bucket_alias(bucket.id, &la.access_key_id, &la.alias)
			.await?;

		if la.allow.read || la.allow.write || la.allow.owner {
			garage
				.bucket_helper()
				.set_bucket_key_permissions(
					bucket.id,
					&la.access_key_id,
					BucketKeyPerm {
						timestamp: now_msec(),
						allow_read: la.allow.read,
						allow_write: la.allow.write,
						allow_owner: la.allow.owner,
					},
				)
				.await?;
		}
	}

	bucket_info_results(garage, bucket.id).await
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
struct CreateBucketRequest {
	global_alias: Option<String>,
	local_alias: Option<CreateBucketLocalAlias>,
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
struct CreateBucketLocalAlias {
	access_key_id: String,
	alias: String,
	#[serde(default)]
	allow: ApiBucketKeyPerm,
}

pub async fn handle_delete_bucket(
	garage: &Arc<Garage>,
	id: String,
) -> Result<Response<ResBody>, Error> {
	let helper = garage.bucket_helper();

	let bucket_id = parse_bucket_id(&id)?;

	let mut bucket = helper.get_existing_bucket(bucket_id).await?;
	let state = bucket.state.as_option().unwrap();

	// Check bucket is empty
	if !helper.is_bucket_empty(bucket_id).await? {
		return Err(CommonError::BucketNotEmpty.into());
	}

	// --- done checking, now commit ---
	// 1. delete authorization from keys that had access
	for (key_id, perm) in bucket.authorized_keys() {
		if perm.is_any() {
			helper
				.set_bucket_key_permissions(bucket.id, key_id, BucketKeyPerm::NO_PERMISSIONS)
				.await?;
		}
	}
	// 2. delete all local aliases
	for ((key_id, alias), _, active) in state.local_aliases.items().iter() {
		if *active {
			helper
				.unset_local_bucket_alias(bucket.id, key_id, alias)
				.await?;
		}
	}
	// 3. delete all global aliases
	for (alias, _, active) in state.aliases.items().iter() {
		if *active {
			helper.purge_global_bucket_alias(bucket.id, alias).await?;
		}
	}

	// 4. delete bucket
	bucket.state = Deletable::delete();
	garage.bucket_table.insert(&bucket).await?;

	Ok(Response::builder()
		.status(StatusCode::NO_CONTENT)
		.body(empty_body())?)
}

pub async fn handle_update_bucket(
	garage: &Arc<Garage>,
	id: String,
	req: Request<IncomingBody>,
) -> Result<Response<ResBody>, Error> {
	let req = parse_json_body::<UpdateBucketRequest, _, Error>(req).await?;
	let bucket_id = parse_bucket_id(&id)?;

	let mut bucket = garage
		.bucket_helper()
		.get_existing_bucket(bucket_id)
		.await?;

	let state = bucket.state.as_option_mut().unwrap();

	if let Some(wa) = req.website_access {
		if wa.enabled {
			state.website_config.update(Some(WebsiteConfig {
				index_document: wa.index_document.ok_or_bad_request(
					"Please specify indexDocument when enabling website access.",
				)?,
				error_document: wa.error_document,
			}));
		} else {
			if wa.index_document.is_some() || wa.error_document.is_some() {
				return Err(Error::bad_request(
					"Cannot specify indexDocument or errorDocument when disabling website access.",
				));
			}
			state.website_config.update(None);
		}
	}

	if let Some(q) = req.quotas {
		state.quotas.update(BucketQuotas {
			max_size: q.max_size,
			max_objects: q.max_objects,
		});
	}

	garage.bucket_table.insert(&bucket).await?;

	bucket_info_results(garage, bucket_id).await
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
struct UpdateBucketRequest {
	website_access: Option<UpdateBucketWebsiteAccess>,
	quotas: Option<ApiBucketQuotas>,
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
struct UpdateBucketWebsiteAccess {
	enabled: bool,
	index_document: Option<String>,
	error_document: Option<String>,
}

// ---- BUCKET/KEY PERMISSIONS ----

pub async fn handle_bucket_change_key_perm(
	garage: &Arc<Garage>,
	req: Request<IncomingBody>,
	new_perm_flag: bool,
) -> Result<Response<ResBody>, Error> {
	let req = parse_json_body::<BucketKeyPermChangeRequest, _, Error>(req).await?;

	let bucket_id = parse_bucket_id(&req.bucket_id)?;

	let bucket = garage
		.bucket_helper()
		.get_existing_bucket(bucket_id)
		.await?;
	let state = bucket.state.as_option().unwrap();

	let key = garage
		.key_helper()
		.get_existing_key(&req.access_key_id)
		.await?;

	let mut perm = state
		.authorized_keys
		.get(&key.key_id)
		.cloned()
		.unwrap_or(BucketKeyPerm::NO_PERMISSIONS);

	if req.permissions.read {
		perm.allow_read = new_perm_flag;
	}
	if req.permissions.write {
		perm.allow_write = new_perm_flag;
	}
	if req.permissions.owner {
		perm.allow_owner = new_perm_flag;
	}

	garage
		.bucket_helper()
		.set_bucket_key_permissions(bucket.id, &key.key_id, perm)
		.await?;

	bucket_info_results(garage, bucket.id).await
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
struct BucketKeyPermChangeRequest {
	bucket_id: String,
	access_key_id: String,
	permissions: ApiBucketKeyPerm,
}

// ---- BUCKET ALIASES ----

pub async fn handle_global_alias_bucket(
	garage: &Arc<Garage>,
	bucket_id: String,
	alias: String,
) -> Result<Response<ResBody>, Error> {
	let bucket_id = parse_bucket_id(&bucket_id)?;

	garage
		.bucket_helper()
		.set_global_bucket_alias(bucket_id, &alias)
		.await?;

	bucket_info_results(garage, bucket_id).await
}

pub async fn handle_global_unalias_bucket(
	garage: &Arc<Garage>,
	bucket_id: String,
	alias: String,
) -> Result<Response<ResBody>, Error> {
	let bucket_id = parse_bucket_id(&bucket_id)?;

	garage
		.bucket_helper()
		.unset_global_bucket_alias(bucket_id, &alias)
		.await?;

	bucket_info_results(garage, bucket_id).await
}

pub async fn handle_local_alias_bucket(
	garage: &Arc<Garage>,
	bucket_id: String,
	access_key_id: String,
	alias: String,
) -> Result<Response<ResBody>, Error> {
	let bucket_id = parse_bucket_id(&bucket_id)?;

	garage
		.bucket_helper()
		.set_local_bucket_alias(bucket_id, &access_key_id, &alias)
		.await?;

	bucket_info_results(garage, bucket_id).await
}

pub async fn handle_local_unalias_bucket(
	garage: &Arc<Garage>,
	bucket_id: String,
	access_key_id: String,
	alias: String,
) -> Result<Response<ResBody>, Error> {
	let bucket_id = parse_bucket_id(&bucket_id)?;

	garage
		.bucket_helper()
		.unset_local_bucket_alias(bucket_id, &access_key_id, &alias)
		.await?;

	bucket_info_results(garage, bucket_id).await
}

// ---- HELPER ----

fn parse_bucket_id(id: &str) -> Result<Uuid, Error> {
	let id_hex = hex::decode(id).ok_or_bad_request("Invalid bucket id")?;
	Ok(Uuid::try_from(&id_hex).ok_or_bad_request("Invalid bucket id")?)
}