//! IBC API endpoints.
//!
//! REST endpoints for Inter-Blockchain Communication:
//! - Chain information
//! - Channel management
//! - Cross-chain transfers
//! - Packet operations

use axum::{
    extract::{Path, Query, State},
    routing::{get, post},
    Json, Router,
};
use serde::{Deserialize, Serialize};

use crate::{
    auth::{require_permission, Authenticated},
    error::ApiResult,
    response::{ApiResponse, PaginationParams},
    routes::AppState,
};

/// Build IBC routes.
pub fn router() -> Router<AppState> {
    Router::new()
        // Chains
        .route("/chains", get(list_chains))
        .route("/chains/:chain_id", get(get_chain))
        .route("/chains/:chain_id/clients", get(get_clients))
        // Channels
        .route("/channels", get(list_channels))
        .route("/channels/:channel_id", get(get_channel))
        .route("/channels/init", post(init_channel))
        // Transfers
        .route("/transfers", get(list_transfers))
        .route("/transfers/send", post(send_transfer))
        .route("/transfers/:transfer_id", get(get_transfer))
        .route("/transfers/routes", get(get_routes))
        // Packets
        .route("/packets/:channel_id", get(list_packets))
        .route("/packets/:channel_id/:sequence", get(get_packet))
        // Relayer
        .route("/relayer/status", get(relayer_status))
        .route("/relayer/register", post(register_relayer))
}

// Types
#[derive(Debug, Serialize)]
pub struct Chain {
    pub chain_id: String,
    pub name: String,
    pub status: String,
    pub rpc_endpoint: String,
    pub latest_height: u64,
    pub active_channels: u32,
}

#[derive(Debug, Serialize)]
pub struct Channel {
    pub channel_id: String,
    pub state: String,
    pub port_id: String,
    pub counterparty_channel_id: String,
    pub connection_id: String,
    pub ordering: String,
    pub version: String,
}

#[derive(Debug, Deserialize)]
pub struct InitChannelRequest {
    pub source_chain: String,
    pub dest_chain: String,
    pub port_id: String,
    pub version: String,
}

#[derive(Debug, Serialize)]
pub struct Transfer {
    pub transfer_id: String,
    pub source_chain: String,
    pub dest_chain: String,
    pub channel_id: String,
    pub asset: String,
    pub amount: String,
    pub sender: String,
    pub receiver: String,
    pub status: String,
    pub created_at: String,
}

#[derive(Debug, Deserialize)]
pub struct SendTransferRequest {
    pub source_chain: String,
    pub dest_chain: String,
    pub channel_id: String,
    pub asset: String,
    pub amount: String,
    pub receiver: String,
    pub memo: Option<String>,
    pub timeout_minutes: Option<u32>,
}

#[derive(Debug, Serialize)]
pub struct TransferRoute {
    pub source_chain: String,
    pub dest_chain: String,
    pub channel_id: String,
    pub estimated_time: String,
    pub fee: String,
}

#[derive(Debug, Serialize)]
pub struct Packet {
    pub sequence: u64,
    pub source_port: String,
    pub source_channel: String,
    pub dest_port: String,
    pub dest_channel: String,
    pub timeout_height: u64,
    pub timeout_timestamp: u64,
    pub data: String,
}

// Handlers
async fn list_chains(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
) -> ApiResult<Json<ApiResponse<Vec<Chain>>>> {
    require_permission(&auth, "read")?;

    let chains = vec![
        Chain {
            chain_id: "cosmoshub-4".to_string(),
            name: "Cosmos Hub".to_string(),
            status: "active".to_string(),
            rpc_endpoint: "https://rpc.cosmos.network".to_string(),
            latest_height: 18000000,
            active_channels: 50,
        },
    ];

    Ok(Json(ApiResponse::success(chains)))
}

async fn get_chain(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Path(chain_id): Path<String>,
) -> ApiResult<Json<ApiResponse<Chain>>> {
    require_permission(&auth, "read")?;

    let chain = Chain {
        chain_id,
        name: "Cosmos Hub".to_string(),
        status: "active".to_string(),
        rpc_endpoint: "https://rpc.cosmos.network".to_string(),
        latest_height: 18000000,
        active_channels: 50,
    };

    Ok(Json(ApiResponse::success(chain)))
}

async fn get_clients(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Path(chain_id): Path<String>,
) -> ApiResult<Json<ApiResponse<Vec<serde_json::Value>>>> {
    require_permission(&auth, "read")?;
    Ok(Json(ApiResponse::success(vec![])))
}

async fn list_channels(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Query(pagination): Query<PaginationParams>,
) -> ApiResult<Json<ApiResponse<Vec<Channel>>>> {
    require_permission(&auth, "read")?;

    let channels = vec![];
    let meta = pagination.to_meta(0);
    Ok(Json(ApiResponse::success_paginated(channels, meta)))
}

async fn get_channel(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Path(channel_id): Path<String>,
) -> ApiResult<Json<ApiResponse<Channel>>> {
    require_permission(&auth, "read")?;

    let channel = Channel {
        channel_id,
        state: "OPEN".to_string(),
        port_id: "transfer".to_string(),
        counterparty_channel_id: "channel-141".to_string(),
        connection_id: "connection-0".to_string(),
        ordering: "UNORDERED".to_string(),
        version: "ics20-1".to_string(),
    };

    Ok(Json(ApiResponse::success(channel)))
}

async fn init_channel(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Json(req): Json<InitChannelRequest>,
) -> ApiResult<Json<ApiResponse<serde_json::Value>>> {
    require_permission(&auth, "write")?;

    let result = serde_json::json!({
        "channel_id": "channel-new",
        "status": "init_sent"
    });

    Ok(Json(ApiResponse::success(result)))
}

async fn list_transfers(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Query(pagination): Query<PaginationParams>,
) -> ApiResult<Json<ApiResponse<Vec<Transfer>>>> {
    require_permission(&auth, "read")?;
    let meta = pagination.to_meta(0);
    Ok(Json(ApiResponse::success_paginated(vec![], meta)))
}

async fn send_transfer(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Json(req): Json<SendTransferRequest>,
) -> ApiResult<Json<ApiResponse<Transfer>>> {
    require_permission(&auth, "write")?;

    let transfer = Transfer {
        transfer_id: "transfer_123".to_string(),
        source_chain: req.source_chain,
        dest_chain: req.dest_chain,
        channel_id: req.channel_id,
        asset: req.asset,
        amount: req.amount,
        sender: "synor1...".to_string(),
        receiver: req.receiver,
        status: "pending".to_string(),
        created_at: "2024-01-15T10:30:00Z".to_string(),
    };

    Ok(Json(ApiResponse::success(transfer)))
}

async fn get_transfer(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Path(transfer_id): Path<String>,
) -> ApiResult<Json<ApiResponse<Transfer>>> {
    require_permission(&auth, "read")?;

    let transfer = Transfer {
        transfer_id,
        source_chain: "cosmoshub-4".to_string(),
        dest_chain: "synor-mainnet".to_string(),
        channel_id: "channel-0".to_string(),
        asset: "uatom".to_string(),
        amount: "1000000".to_string(),
        sender: "cosmos1...".to_string(),
        receiver: "synor1...".to_string(),
        status: "completed".to_string(),
        created_at: "2024-01-15T10:30:00Z".to_string(),
    };

    Ok(Json(ApiResponse::success(transfer)))
}

async fn get_routes(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Query(params): Query<serde_json::Value>,
) -> ApiResult<Json<ApiResponse<Vec<TransferRoute>>>> {
    require_permission(&auth, "read")?;

    let routes = vec![
        TransferRoute {
            source_chain: "cosmoshub-4".to_string(),
            dest_chain: "synor-mainnet".to_string(),
            channel_id: "channel-0".to_string(),
            estimated_time: "30s".to_string(),
            fee: "0.001 ATOM".to_string(),
        },
    ];

    Ok(Json(ApiResponse::success(routes)))
}

async fn list_packets(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Path(channel_id): Path<String>,
    Query(pagination): Query<PaginationParams>,
) -> ApiResult<Json<ApiResponse<Vec<Packet>>>> {
    require_permission(&auth, "read")?;
    let meta = pagination.to_meta(0);
    Ok(Json(ApiResponse::success_paginated(vec![], meta)))
}

async fn get_packet(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Path((channel_id, sequence)): Path<(String, u64)>,
) -> ApiResult<Json<ApiResponse<Packet>>> {
    require_permission(&auth, "read")?;

    let packet = Packet {
        sequence,
        source_port: "transfer".to_string(),
        source_channel: channel_id.clone(),
        dest_port: "transfer".to_string(),
        dest_channel: "channel-141".to_string(),
        timeout_height: 0,
        timeout_timestamp: 1705400000,
        data: "base64data...".to_string(),
    };

    Ok(Json(ApiResponse::success(packet)))
}

async fn relayer_status(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
) -> ApiResult<Json<ApiResponse<serde_json::Value>>> {
    require_permission(&auth, "read")?;

    let status = serde_json::json!({
        "active_relayers": 10,
        "pending_packets": 5,
        "total_relayed": 10000
    });

    Ok(Json(ApiResponse::success(status)))
}

async fn register_relayer(
    State(state): State<AppState>,
    Authenticated(auth): Authenticated,
    Json(req): Json<serde_json::Value>,
) -> ApiResult<Json<ApiResponse<serde_json::Value>>> {
    require_permission(&auth, "write")?;

    let result = serde_json::json!({
        "relayer_id": "relayer_123",
        "status": "registered"
    });

    Ok(Json(ApiResponse::success(result)))
}
