//! This module defines a bunch of internal types used solely for querying into RPC
//! methods to retrieve info about what's on the chain. Note that the types defined
//! are exposed as-is for users to reference in their own functions or structs as
//! needed. These types cannot be created outside of workspaces. To use them, refer
//! to surface level types like [`Account`], [`Contract`] and [`Worker`].
//!
//! For example, to query into downloading contract state:
//! ```
//! use workspaces::{AccountId, Network, Worker};
//! use workspaces::rpc::query::{Query, ViewState};
//!
//! async fn my_func(worker: &Worker<impl Network>) -> anyhow::Result<()> {
//!     let contract_id: AccountId = "some-contract.near".parse()?;
//!     let query: Query<'_, ViewState> = worker.view_state(&contract_id);
//!     let bytes = query.await?;
//!     Ok(())
//! }
//! ```
//! But most of the time, we do not need to worry about these types as they are
//! meant to be transitory, and only exist while calling into their immediate
//! methods. So the above example should look more like the following:
//! ```ignore
//! async fn my_func(worker: &Worker<impl Network>) -> anyhow::Result<()> {
//!     let contract_id: AccountId = "some-contract.near".parse()?;
//!     let bytes = worker.view_state(&contract_id).await?;
//!     Ok(())
//! }
//! ```
//!
//! [`Account`]: crate::Account
//! [`Contract`]: crate::Contract
//! [`Worker`]: crate::Worker

use std::collections::HashMap;
use std::fmt::{Debug, Display};

use near_account_id::AccountId;
use near_jsonrpc_client::methods::query::RpcQueryResponse;
use near_jsonrpc_client::methods::{self, RpcMethod};
use near_jsonrpc_primitives::types::chunks::ChunkReference;
use near_jsonrpc_primitives::types::query::QueryResponseKind;
use near_primitives::types::{BlockId, BlockReference, StoreKey};
use near_primitives::views::{BlockView, QueryRequest};

use crate::error::RpcErrorCode;
use crate::operations::Function;
use crate::result::ViewResultDetails;
use crate::rpc::client::Client;
use crate::rpc::{tool, BoxFuture};
use crate::types::{AccessKey, AccessKeyInfo, Balance, BlockHeight, Finality, PublicKey, ShardId};
use crate::{AccountDetails, Block, Chunk, CryptoHash, Result};

/// `Query` object allows creating queries into the network of our choice. This object is
/// usually given from making calls from other functions such as [`view_state`].
///
/// [`view_state`]: crate::worker::Worker::view_state
pub struct Query<'a, T> {
    pub(crate) method: T,
    pub(crate) client: &'a Client,
    pub(crate) block_ref: Option<BlockReference>,
}

impl<'a, T> Query<'a, T> {
    pub(crate) fn new(client: &'a Client, method: T) -> Self {
        Self {
            method,
            client,
            block_ref: None,
        }
    }

    /// Specify at which block height to query from. Note that only archival
    /// networks will have the full history while networks like mainnet or testnet will
    /// only have the history from 5 or less epochs ago.
    pub fn block_height(mut self, height: BlockHeight) -> Self {
        self.block_ref = Some(BlockId::Height(height).into());
        self
    }

    /// Specify at which block hash to query from. Note that only archival
    /// networks will have the full history while networks like mainnet or testnet will
    /// only have the history from 5 or less epochs ago.
    pub fn block_hash(mut self, hash: CryptoHash) -> Self {
        self.block_ref = Some(BlockId::Hash(near_primitives::hash::CryptoHash(hash.0)).into());
        self
    }
}

// Constrained to RpcQueryRequest, since methods like GasPrice only take block_id but not Finality.
impl<'a, T> Query<'a, T>
where
    T: ProcessQuery<Method = methods::query::RpcQueryRequest>,
{
    /// Specify at which block [`Finality`] to query from.
    pub fn finality(mut self, value: Finality) -> Self {
        self.block_ref = Some(value.into());
        self
    }

    pub(crate) fn block_reference(mut self, value: BlockReference) -> Self {
        self.block_ref = Some(value);
        self
    }
}

impl<'a, T, R> std::future::IntoFuture for Query<'a, T>
where
    T: ProcessQuery<Output = R> + Send + Sync + 'static,
    <T as ProcessQuery>::Method: RpcMethod + Debug + Send + Sync,
    <<T as ProcessQuery>::Method as RpcMethod>::Response: Debug + Send + Sync,
    <<T as ProcessQuery>::Method as RpcMethod>::Error: Debug + Display + Send + Sync,
{
    type Output = Result<R>;

    // TODO: boxed future required due to impl Trait as type alias being unstable. So once
    // https://github.com/rust-lang/rust/issues/63063 is resolved, we can move to that instead.
    type IntoFuture = BoxFuture<'a, Self::Output>;

    fn into_future(self) -> Self::IntoFuture {
        Box::pin(async move {
            let block_reference = self.block_ref.unwrap_or_else(BlockReference::latest);
            let resp = self
                .client
                .query(self.method.into_request(block_reference)?)
                .await
                .map_err(|e| RpcErrorCode::QueryFailure.custom(e))?;

            T::from_response(resp)
        })
    }
}

// Note: this trait is exposed publicly due to constraining with the impl offering `finality`.
/// Trait used as a converter from WorkspaceRequest to near-rpc request, and from near-rpc
/// response to a WorkspaceResult. Mostly used internally to facilitate syntax sugar for performing
/// RPC requests with async builders.
pub trait ProcessQuery {
    // TODO: associated default type is unstable. So for now, will require writing
    // the manual impls for query_request
    /// Method for doing the internal RPC request to the network of our choosing.
    type Method: RpcMethod;

    /// Expected output after performing a query. This is mainly to convert over
    /// the type from near-primitives to a workspace type.
    type Output;

    /// Convert into the Request object that is required to perform the RPC request.
    fn into_request(self, block_ref: BlockReference) -> Result<Self::Method>;

    /// Convert the response from the RPC request to a type of our choosing, mainly to conform
    /// to workspaces related types from the near-primitives or json types from the network.
    fn from_response(resp: <Self::Method as RpcMethod>::Response) -> Result<Self::Output>;
}

pub struct ViewFunction {
    pub(crate) account_id: AccountId,
    pub(crate) function: Function,
}

pub struct ViewCode {
    pub(crate) account_id: AccountId,
}

pub struct ViewAccount {
    pub(crate) account_id: AccountId,
}

pub struct ViewBlock;

pub struct ViewState {
    account_id: AccountId,
    prefix: Option<Vec<u8>>,
}

pub struct ViewAccessKey {
    pub(crate) account_id: AccountId,
    pub(crate) public_key: PublicKey,
}

pub struct ViewAccessKeyList {
    pub(crate) account_id: AccountId,
}

pub struct GasPrice;

impl ProcessQuery for ViewFunction {
    type Method = methods::query::RpcQueryRequest;
    type Output = ViewResultDetails;

    fn into_request(self, block_reference: BlockReference) -> Result<Self::Method> {
        Ok(Self::Method {
            block_reference,
            request: QueryRequest::CallFunction {
                account_id: self.account_id,
                method_name: self.function.name,
                args: self.function.args?.into(),
            },
        })
    }

    fn from_response(resp: RpcQueryResponse) -> Result<Self::Output> {
        match resp.kind {
            QueryResponseKind::CallResult(result) => Ok(result.into()),
            _ => Err(RpcErrorCode::QueryReturnedInvalidData.message("while querying account")),
        }
    }
}

// Specific builder methods attached to a ViewFunction.
impl Query<'_, ViewFunction> {
    /// Provide the arguments for the call. These args are serialized bytes from either
    /// a JSON or Borsh serializable set of arguments. To use the more specific versions
    /// with better quality of life, use `args_json` or `args_borsh`.
    pub fn args(mut self, args: Vec<u8>) -> Self {
        self.method.function = self.method.function.args(args);
        self
    }

    /// Similiar to `args`, specify an argument that is JSON serializable and can be
    /// accepted by the equivalent contract. Recommend to use something like
    /// `serde_json::json!` macro to easily serialize the arguments.
    pub fn args_json<U: serde::Serialize>(mut self, args: U) -> Self {
        self.method.function = self.method.function.args_json(args);
        self
    }

    /// Similiar to `args`, specify an argument that is borsh serializable and can be
    /// accepted by the equivalent contract.
    pub fn args_borsh<U: borsh::BorshSerialize>(mut self, args: U) -> Self {
        self.method.function = self.method.function.args_borsh(args);
        self
    }
}

impl ProcessQuery for ViewCode {
    type Method = methods::query::RpcQueryRequest;
    type Output = Vec<u8>;

    fn into_request(self, block_reference: BlockReference) -> Result<Self::Method> {
        Ok(Self::Method {
            block_reference,
            request: QueryRequest::ViewCode {
                account_id: self.account_id,
            },
        })
    }

    fn from_response(resp: RpcQueryResponse) -> Result<Self::Output> {
        match resp.kind {
            QueryResponseKind::ViewCode(contract) => Ok(contract.code),
            _ => Err(RpcErrorCode::QueryReturnedInvalidData.message("while querying code")),
        }
    }
}

impl ProcessQuery for ViewAccount {
    type Method = methods::query::RpcQueryRequest;
    type Output = AccountDetails;

    fn into_request(self, block_reference: BlockReference) -> Result<Self::Method> {
        Ok(Self::Method {
            block_reference,
            request: QueryRequest::ViewAccount {
                account_id: self.account_id,
            },
        })
    }

    fn from_response(resp: RpcQueryResponse) -> Result<Self::Output> {
        match resp.kind {
            QueryResponseKind::ViewAccount(account) => Ok(account.into()),
            _ => Err(RpcErrorCode::QueryReturnedInvalidData.message("while querying account")),
        }
    }
}

impl ProcessQuery for ViewBlock {
    type Method = methods::block::RpcBlockRequest;
    type Output = Block;

    fn into_request(self, block_reference: BlockReference) -> Result<Self::Method> {
        Ok(Self::Method { block_reference })
    }

    fn from_response(view: BlockView) -> Result<Self::Output> {
        Ok(view.into())
    }
}

impl ProcessQuery for ViewState {
    type Method = methods::query::RpcQueryRequest;
    type Output = HashMap<Vec<u8>, Vec<u8>>;

    fn into_request(self, block_reference: BlockReference) -> Result<Self::Method> {
        Ok(Self::Method {
            block_reference,
            request: QueryRequest::ViewState {
                account_id: self.account_id,
                prefix: StoreKey::from(self.prefix.map(Vec::from).unwrap_or_default()),
                include_proof: false,
            },
        })
    }

    fn from_response(resp: <Self::Method as RpcMethod>::Response) -> Result<Self::Output> {
        match resp.kind {
            QueryResponseKind::ViewState(state) => Ok(tool::into_state_map(state.values)),
            _ => Err(RpcErrorCode::QueryReturnedInvalidData.message("while querying state")),
        }
    }
}

impl<'a> Query<'a, ViewState> {
    pub(crate) fn view_state(client: &'a Client, id: &AccountId) -> Self {
        Self::new(
            client,
            ViewState {
                account_id: id.clone(),
                prefix: None,
            },
        )
    }

    /// Set the prefix for viewing the state.
    pub fn prefix(mut self, value: &[u8]) -> Self {
        self.method.prefix = Some(value.into());
        self
    }
}

impl ProcessQuery for ViewAccessKey {
    type Method = methods::query::RpcQueryRequest;
    type Output = AccessKey;

    fn into_request(self, block_reference: BlockReference) -> Result<Self::Method> {
        Ok(Self::Method {
            block_reference,
            request: QueryRequest::ViewAccessKey {
                account_id: self.account_id,
                public_key: self.public_key.into(),
            },
        })
    }

    fn from_response(resp: <Self::Method as RpcMethod>::Response) -> Result<Self::Output> {
        match resp.kind {
            QueryResponseKind::AccessKey(key) => Ok(key.into()),
            _ => Err(RpcErrorCode::QueryReturnedInvalidData.message("while querying access key")),
        }
    }
}

impl ProcessQuery for ViewAccessKeyList {
    type Method = methods::query::RpcQueryRequest;
    type Output = Vec<AccessKeyInfo>;

    fn into_request(self, block_reference: BlockReference) -> Result<Self::Method> {
        Ok(Self::Method {
            block_reference,
            request: QueryRequest::ViewAccessKeyList {
                account_id: self.account_id,
            },
        })
    }

    fn from_response(resp: <Self::Method as RpcMethod>::Response) -> Result<Self::Output> {
        match resp.kind {
            QueryResponseKind::AccessKeyList(keylist) => {
                Ok(keylist.keys.into_iter().map(Into::into).collect())
            }
            _ => Err(RpcErrorCode::QueryReturnedInvalidData.message("while querying access keys")),
        }
    }
}

impl ProcessQuery for GasPrice {
    type Method = methods::gas_price::RpcGasPriceRequest;
    type Output = Balance;

    fn into_request(self, block_ref: BlockReference) -> Result<Self::Method> {
        let block_id = match block_ref {
            // User provided input via `block_hash` or `block_height` functions.
            BlockReference::BlockId(block_id) => Some(block_id),
            // default case, set by `Query` struct via BlockReference::latest.
            BlockReference::Finality(_finality) => None,
            // Should not be reachable, unless code got changed.
            BlockReference::SyncCheckpoint(point) => {
                return Err(RpcErrorCode::QueryFailure.message(format!(
                    "Cannot supply sync checkpoint to gas price: {point:?}. Potential API bug?"
                )))
            }
        };

        Ok(Self::Method { block_id })
    }

    fn from_response(resp: <Self::Method as RpcMethod>::Response) -> Result<Self::Output> {
        Ok(resp.gas_price)
    }
}

/// Query object used to query for chunk related details at a specific `ChunkReference` which
/// consists of either a chunk [`CryptoHash`], or a `BlockShardId` (which consists of [`ShardId`]
/// and either block [`CryptoHash`] or [`BlockHeight`]).
///
/// The default behavior where a `ChunkReference` is not supplied will use a `BlockShardId`
/// referencing the lastest block `CryptoHash` with `ShardId` of 0.
pub struct QueryChunk<'a> {
    client: &'a Client,
    chunk_ref: Option<ChunkReference>,
}

impl<'a> QueryChunk<'a> {
    pub(crate) fn new(client: &'a Client) -> Self {
        Self {
            client,
            chunk_ref: None,
        }
    }

    /// Specify at which block hash and shard id to query the chunk from. Note that only
    /// archival networks will have the full history while networks like mainnet or testnet
    /// will only have the history from 5 or less epochs ago.
    pub fn block_hash_and_shard(mut self, hash: CryptoHash, shard_id: ShardId) -> Self {
        self.chunk_ref = Some(ChunkReference::BlockShardId {
            block_id: BlockId::Hash(near_primitives::hash::CryptoHash(hash.0)),
            shard_id,
        });
        self
    }

    /// Specify at which block height and shard id to query the chunk from. Note that only
    /// archival networks will have the full history while networks like mainnet or testnet
    /// will only have the history from 5 or less epochs ago.
    pub fn block_height_and_shard(mut self, height: BlockHeight, shard_id: ShardId) -> Self {
        self.chunk_ref = Some(ChunkReference::BlockShardId {
            block_id: BlockId::Height(height),
            shard_id,
        });
        self
    }

    /// Specify at which chunk hash to query the chunk from.
    pub fn chunk_hash(mut self, hash: CryptoHash) -> Self {
        self.chunk_ref = Some(ChunkReference::ChunkHash {
            chunk_id: near_primitives::hash::CryptoHash(hash.0),
        });
        self
    }
}

impl<'a> std::future::IntoFuture for QueryChunk<'a> {
    type Output = Result<Chunk>;
    type IntoFuture = BoxFuture<'a, Self::Output>;

    fn into_future(self) -> Self::IntoFuture {
        Box::pin(async move {
            let chunk_reference = if let Some(chunk_ref) = self.chunk_ref {
                chunk_ref
            } else {
                // Use the latest block hash in the case the user doesn't supply the ChunkReference. Note that
                // shard_id 0 is used in the default case.
                let block_view = self.client.view_block(None).await?;
                ChunkReference::BlockShardId {
                    block_id: BlockId::Hash(block_view.header.hash),
                    shard_id: 0,
                }
            };

            let chunk_view = self
                .client
                .query(methods::chunk::RpcChunkRequest { chunk_reference })
                .await
                .map_err(|e| RpcErrorCode::QueryFailure.custom(e))?;

            Ok(chunk_view.into())
        })
    }
}