// Copyright (c) 2017-2026 Lethean (https://lt.hn)
// SPDX-License-Identifier: EUPL-1.2

package node

import (
	"bytes"
	"io"
	"net/http"
)

// info, err := node.GetChainInfo(LetheanMainnetDaemon)
// pools := node.DiscoverPools(LetheanTestnetDaemon)
const (
	LetheanTestnetDaemon = "http://127.0.0.1:46941"
	LetheanMainnetDaemon = "http://127.0.0.1:36941"
	LetheanTestnetPool   = "stratum+tcp://pool.lthn.io:5555"
	LetheanMainnetPool   = "stratum+tcp://pool.lthn.io:3333"
)

// info, err := node.GetChainInfo("http://127.0.0.1:46941")
// if info.Synced { log("height:", info.Height, "aliases:", info.AliasCount) }
type ChainInfo struct {
	Height     uint64 `json:"height"`
	AliasCount int    `json:"alias_count"`
	Synced     bool   `json:"synced"`
	PoolSize   int    `json:"tx_pool_size"`
	Difficulty uint64 `json:"difficulty"`
}

// pools := node.DiscoverPools("http://127.0.0.1:46941")
// for _, pool := range pools { log(pool.Name, pool.Endpoint) }
type PoolGateway struct {
	Name     string `json:"name"`
	Address  string `json:"address"`
	Capabilities string `json:"caps"`
	Endpoint string `json:"endpoint"`
}

// info, err := node.GetChainInfo("http://127.0.0.1:46941")
// if err == nil && info.Synced { log("chain height:", info.Height) }
func GetChainInfo(daemonURL string) (*ChainInfo, error) {
	requestBody := `{"jsonrpc":"2.0","id":"0","method":"getinfo","params":{}}`
	response, err := http.Post(daemonURL+"/json_rpc", "application/json", bytes.NewReader([]byte(requestBody)))
	if err != nil {
		return nil, err
	}
	defer response.Body.Close()
	responseBody, _ := io.ReadAll(response.Body)

	var rpcResponse struct {
		Result ChainInfo `json:"result"`
	}
	if err := UnmarshalJSON(responseBody, &rpcResponse); err != nil {
		return nil, err
	}
	rpcResponse.Result.Synced = rpcResponse.Result.Height > 0
	return &rpcResponse.Result, nil
}

// pools := node.DiscoverPools("http://127.0.0.1:46941")
// for _, pool := range pools { log(pool.Name, pool.Endpoint) }
func DiscoverPools(daemonURL string) []PoolGateway {
	requestBody := `{"jsonrpc":"2.0","id":"0","method":"get_all_alias_details","params":{}}`
	response, err := http.Post(daemonURL+"/json_rpc", "application/json", bytes.NewReader([]byte(requestBody)))
	if err != nil {
		return nil
	}
	defer response.Body.Close()
	responseBody, _ := io.ReadAll(response.Body)

	var rpcResponse struct {
		Result struct {
			Aliases []struct {
				Alias   string `json:"alias"`
				Address string `json:"address"`
				Comment string `json:"comment"`
			} `json:"aliases"`
		} `json:"result"`
	}
	UnmarshalJSON(responseBody, &rpcResponse) //nolint:errcheck

	var pools []PoolGateway
	for _, alias := range rpcResponse.Result.Aliases {
		if !bytes.Contains([]byte(alias.Comment), []byte("pool")) {
			continue
		}
		commentFields := parseComment(alias.Comment)
		pools = append(pools, PoolGateway{
			Name:         alias.Alias,
			Address:      alias.Address,
			Capabilities: commentFields["cap"],
			Endpoint:     "stratum+tcp://" + alias.Alias + ".lthn:5555",
		})
	}
	return pools
}

// gateways := node.DiscoverGateways("http://127.0.0.1:46941")
// for _, gateway := range gateways { log(gateway.Name, gateway.Endpoint) }
func DiscoverGateways(daemonURL string) []PoolGateway {
	requestBody := `{"jsonrpc":"2.0","id":"0","method":"get_all_alias_details","params":{}}`
	response, err := http.Post(daemonURL+"/json_rpc", "application/json", bytes.NewReader([]byte(requestBody)))
	if err != nil {
		return nil
	}
	defer response.Body.Close()
	responseBody, _ := io.ReadAll(response.Body)

	var rpcResponse struct {
		Result struct {
			Aliases []struct {
				Alias   string `json:"alias"`
				Address string `json:"address"`
				Comment string `json:"comment"`
			} `json:"aliases"`
		} `json:"result"`
	}
	UnmarshalJSON(responseBody, &rpcResponse) //nolint:errcheck

	var gateways []PoolGateway
	for _, alias := range rpcResponse.Result.Aliases {
		if !bytes.Contains([]byte(alias.Comment), []byte("type=gateway")) {
			continue
		}
		commentFields := parseComment(alias.Comment)
		gateways = append(gateways, PoolGateway{
			Name:         alias.Alias,
			Address:      alias.Address,
			Capabilities: commentFields["cap"],
			Endpoint:     alias.Alias + ".lthn",
		})
	}
	return gateways
}

// parsed := parseComment("cap=pool;endpoint=stratum+tcp://pool.lthn.io:3333")
// parsed["cap"]      // "pool"
// parsed["endpoint"] // "stratum+tcp://pool.lthn.io:3333"
func parseComment(comment string) map[string]string {
	fields := make(map[string]string)
	for _, segment := range bytes.Split([]byte(comment), []byte(";")) {
		separatorIndex := bytes.IndexByte(segment, '=')
		if separatorIndex > 0 {
			fields[string(segment[:separatorIndex])] = string(segment[separatorIndex+1:])
		}
	}
	return fields
}