// Copyright 2024 The NativeLink Authors. All rights reserved.

//

// Licensed under the Functional Source License, Version 1.1, Apache 2.0 Future License (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//    See LICENSE file for details

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

use std::collections::HashMap;

#[cfg(feature = "dev-schema")]

use schemars::JsonSchema;

use serde::{Deserialize, Serialize};

use crate::serde_utils::{

    convert_duration_with_shellexpand, convert_duration_with_shellexpand_and_negative,

    convert_numeric_with_shellexpand, convert_string_with_shellexpand,

};

use crate::stores::{GrpcEndpoint, Retry, StoreRefName};

#[derive(Deserialize, Serialize, Debug)]

#[serde(rename_all = "snake_case")]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub enum SchedulerSpec {

    Simple(SimpleSpec),

    Grpc(GrpcSpec),

    CacheLookup(CacheLookupSpec),

    PropertyModifier(PropertyModifierSpec),

    HistoricalResource(HistoricalResourceSpec),

}

/// When the scheduler matches tasks to workers that are capable of running

/// the task, this value will be used to determine how the property is treated.

#[derive(Deserialize, Serialize, Debug, Clone, Copy, Hash, Eq, PartialEq)]

#[serde(rename_all = "snake_case")]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub enum PropertyType {

    /// Requires the platform property to be a u64 and when the scheduler looks

    /// for appropriate worker nodes that are capable of executing the task,

    /// the task will not run on a node that has less than this value.

    Minimum,

    /// Requires the platform property to be a string and when the scheduler

    /// looks for appropriate worker nodes that are capable of executing the

    /// task, the task will not run on a node that does not have this property

    /// set to the value with exact string match.

    Exact,

    /// Does not restrict on this value and instead will be passed to the worker

    /// as an informational piece.

    /// TODO(palfrey) In the future this will be used by the scheduler and worker

    /// to cause the scheduler to prefer certain workers over others, but not

    /// restrict them based on these values.

    Priority,

    //// Allows jobs to be requested with said key, but without requiring workers

    //// to have that key

    Ignore,

}

/// When a worker is being searched for to run a job, this will be used

/// on how to choose which worker should run the job when multiple

/// workers are able to run the task.

#[derive(Copy, Clone, Deserialize, Serialize, Debug, Default)]

#[serde(rename_all = "snake_case")]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub enum WorkerAllocationStrategy {

    /// Prefer workers that have been least recently used to run a job.

    #[default]

    LeastRecentlyUsed,

    /// Prefer workers that have been most recently used to run a job.

    MostRecentlyUsed,

}

// defaults to every 10s

const fn default_worker_match_logging_interval_s() -> i64 {

    10

}

// defaults to every 5s

const fn default_fallback_match_interval_s() -> i64 {

    5

}

#[derive(Deserialize, Serialize, Debug, Default)]

#[serde(deny_unknown_fields)]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub struct SimpleSpec {

    /// A list of supported platform properties mapped to how these properties

    /// are used when the scheduler looks for worker nodes capable of running

    /// the task.

    ///

    /// For example, a value of:

    /// ```json

    /// { "cpu_count": "minimum", "cpu_arch": "exact" }

    /// ```

    /// With a job that contains:

    /// ```json

    /// { "cpu_count": "8", "cpu_arch": "arm" }

    /// ```

    /// Will result in the scheduler filtering out any workers that do not have

    /// `"cpu_arch" = "arm"` and filter out any workers that have less than 8 CPU

    /// cores available.

    ///

    /// The property names here must match the property keys provided by the

    /// worker nodes when they join the pool. In other words, the workers will

    /// publish their capabilities to the scheduler when they join the worker

    /// pool. If the worker fails to notify the scheduler of its (for example)

    /// `"cpu_arch"`, the scheduler will never send any jobs to it, if all jobs

    /// have the `"cpu_arch"` label. We have no special treatment of any platform

    /// property labels other and entirely driven by worker configs and this

    /// config.

    pub supported_platform_properties: Option<HashMap<String, PropertyType>>,

    /// The amount of time to retain completed actions for in case

    /// a `WaitExecution` is called after the action has completed.

    /// Default: 60 seconds

    #[serde(default, deserialize_with = "convert_duration_with_shellexpand")]

    pub retain_completed_for_s: u32,

    /// Mark operations as completed with error if no client has updated them

    /// within this duration.

    /// Default: 60 seconds

    #[serde(default, deserialize_with = "convert_duration_with_shellexpand")]

    pub client_action_timeout_s: u64,

    /// Remove workers from pool once the worker has not responded in this

    /// amount of time in seconds.

    /// Default: 5 seconds

    #[serde(default, deserialize_with = "convert_duration_with_shellexpand")]

    pub worker_timeout_s: u64,

    /// Maximum time (seconds) an action can stay in Executing state without

    /// any worker update before being timed out and re-queued.

    /// This applies regardless of worker keepalive status, catching cases

    /// where a worker is alive (sending keepalives) but stuck on a specific

    /// action. Set to 0 to disable (relies only on `worker_timeout_s`).

    ///

    /// Default: 0 (disabled)

    #[serde(default, deserialize_with = "convert_duration_with_shellexpand")]

    pub max_action_executing_timeout_s: u64,

    /// If a job returns an internal error or times out this many times when

    /// attempting to run on a worker the scheduler will return the last error

    /// to the client. Jobs will be retried and this configuration is to help

    /// prevent one rogue job from infinitely retrying and taking up a lot of

    /// resources when the task itself is the one causing the server to go

    /// into a bad state.

    /// Default: 3

    #[serde(default, deserialize_with = "convert_numeric_with_shellexpand")]

    pub max_job_retries: usize,

    /// The strategy used to assign workers jobs.

    #[serde(default)]

    pub allocation_strategy: WorkerAllocationStrategy,

    /// The storage backend to use for the scheduler.

    /// Default: memory

    pub experimental_backend: Option<ExperimentalSimpleSchedulerBackend>,

    /// Every N seconds, do logging of worker matching

    /// e.g. "worker busy", "can't find any worker"

    /// Defaults to 10s. Can be set to -1 to disable

    #[serde(

        default = "default_worker_match_logging_interval_s",

        deserialize_with = "convert_duration_with_shellexpand_and_negative"

    )]

    pub worker_match_logging_interval_s: i64,

    /// Every N seconds, run a worker matching pass even if no task or worker

    /// change notification arrived. This is a safety net for missed

    /// notifications and for scheduler backends with eventually consistent

    /// searches (for example Redis), where an operation that was re-queued

    /// may not be visible to the search triggered by its own notification.

    /// Without this, such an operation can stay queued until an unrelated

    /// event triggers another matching pass.

    /// Defaults to 5s. Zero or any negative value disables it.

    #[serde(

        default = "default_fallback_match_interval_s",

        deserialize_with = "convert_duration_with_shellexpand_and_negative"

    )]

    pub fallback_match_interval_s: i64,

}

#[derive(Deserialize, Serialize, Debug)]

#[serde(rename_all = "snake_case")]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub enum ExperimentalSimpleSchedulerBackend {

    /// Use an in-memory store for the scheduler.

    Memory,

    /// Use a redis store for the scheduler.

    Redis(ExperimentalRedisSchedulerBackend),

}

#[derive(Deserialize, Serialize, Debug, Default)]

#[serde(deny_unknown_fields)]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub struct ExperimentalRedisSchedulerBackend {

    /// A reference to the redis store to use for the scheduler.

    /// Note: This MUST resolve to a `RedisSpec`.

    pub redis_store: StoreRefName,

}

/// A scheduler that forwards requests to an upstream scheduler. This

/// is useful to use when doing some kind of local action cache or CAS away from

/// the main cluster of workers. In general, it's more efficient to point the

/// build at the main scheduler directly though.

#[derive(Deserialize, Serialize, Debug)]

#[serde(deny_unknown_fields)]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub struct GrpcSpec {

    /// The upstream scheduler to forward requests to.

    pub endpoint: GrpcEndpoint,

    /// Retry configuration to use when a network request fails.

    #[serde(default)]

    pub retry: Retry,

    /// Limit the number of simultaneous upstream requests to this many. A

    /// value of zero is treated as unlimited. If the limit is reached the

    /// request is queued.

    /// Default: unlimited

    #[serde(default, deserialize_with = "convert_numeric_with_shellexpand")]

    pub max_concurrent_requests: usize,

    /// The number of connections to make to each specified endpoint to balance

    /// the load over multiple TCP connections.

    /// Default: 1.

    #[serde(default, deserialize_with = "convert_numeric_with_shellexpand")]

    pub connections_per_endpoint: usize,

}

#[derive(Deserialize, Serialize, Debug)]

#[serde(deny_unknown_fields)]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub struct CacheLookupSpec {

    /// The reference to the action cache store used to return cached

    /// actions from rather than running them again.

    /// To prevent unintended issues, this store should probably be a `CompletenessCheckingSpec`.

    pub ac_store: StoreRefName,

    /// The nested scheduler to use if cache lookup fails.

    pub scheduler: Box<SchedulerSpec>,

}

#[derive(Deserialize, Serialize, Debug, Clone)]

#[serde(deny_unknown_fields)]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub struct PlatformPropertyAddition {

    /// The name of the property to add.

    pub name: String,

    /// The value to assign to the property.

    pub value: String,

}

#[derive(Deserialize, Serialize, Debug, Clone)]

#[serde(deny_unknown_fields)]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub struct PlatformPropertyReplacement {

    /// The name of the property to replace.

    pub name: String,

    /// The value to match against, if unset then any instance matches.

    #[serde(default)]

    pub value: Option<String>,

    /// The new name of the property.

    pub new_name: String,

    /// The value to assign to the property, if unset will remain the same.

    #[serde(default)]

    pub new_value: Option<String>,

}

#[derive(Deserialize, Serialize, Debug, Clone)]

#[serde(rename_all = "snake_case")]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub enum PropertyModification {

    /// Add a property to the action properties.

    Add(PlatformPropertyAddition),

    /// Remove a named property from the action.

    Remove(String),

    /// If a property is found, then replace it with another one.

    Replace(PlatformPropertyReplacement),

}

#[derive(Deserialize, Serialize, Debug)]

#[serde(deny_unknown_fields)]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub struct PropertyModifierSpec {

    /// A list of modifications to perform to incoming actions for the nested

    /// scheduler. These are performed in order and blindly, so removing a

    /// property that doesn't exist is fine and overwriting an existing property

    /// is also fine. If adding properties that do not exist in the nested

    /// scheduler is not supported and will likely cause unexpected behaviour.

    pub modifications: Vec<PropertyModification>,

    /// The nested scheduler to use after modifying the properties.

    pub scheduler: Box<SchedulerSpec>,

}

const fn default_historical_resource_refresh_interval_s() -> u64 {

    30

}

fn default_historical_resource_cpu_property_name() -> String {

    "cpu_count".to_string()

}

fn default_historical_resource_memory_property_name() -> String {

    "memory_kb".to_string()

}

#[derive(Deserialize, Serialize, Debug)]

#[serde(deny_unknown_fields)]

#[cfg_attr(feature = "dev-schema", derive(JsonSchema))]

pub struct HistoricalResourceSpec {

    /// JSON file containing historical resource hints keyed by Bazel

    /// `RequestMetadata` `target_id` and/or `action_mnemonic`.

    ///

    /// Supported file shapes:

    /// ```json

    /// [

    ///   { "target_id": "//pkg:test", "action_mnemonic": "TestRunner", "cpu_count": 2, "memory_kb": 12582912 }

    /// ]

    /// ```

    /// or:

    /// ```json

    /// { "hints": [ ... ] }

    /// ```

    #[serde(deserialize_with = "convert_string_with_shellexpand")]

    pub hints_file: String,

    /// Reload interval for `hints_file`. Set to 0 to load once.

    /// Default: 30 seconds

    #[serde(

        default = "default_historical_resource_refresh_interval_s",

        deserialize_with = "convert_duration_with_shellexpand"

    )]

    pub refresh_interval_s: u64,

    /// Platform property name used for CPU minimums.

    /// Default: `cpu_count`

    #[serde(

        default = "default_historical_resource_cpu_property_name",

        deserialize_with = "convert_string_with_shellexpand"

    )]

    pub cpu_property_name: String,

    /// Platform property name used for memory minimums, expressed in KiB.

    /// Default: `memory_kb`

    #[serde(

        default = "default_historical_resource_memory_property_name",

        deserialize_with = "convert_string_with_shellexpand"

    )]

    pub memory_property_name: String,

    /// The nested scheduler to use after applying resource hints.

    pub scheduler: Box<SchedulerSpec>,

}