package terra

import (
	"context"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"strconv"
	"time"

	"go.uber.org/ratelimit"
)

// TerraSDK is a client for the Terra blockchain.
type TerraSDK struct {
	url    string
	client *http.Client
	rl     ratelimit.Limiter
}

// TerraTrx is a transaction on the Terra blockchain.
type TerraTrx struct {
}

// NewTerraSDK creates a new TerraSDK.
func NewTerraSDK(url string, rl ratelimit.Limiter) *TerraSDK {
	return &TerraSDK{
		url:    url,
		rl:     rl,
		client: &http.Client{},
	}
}

type LastBlockResponse struct {
	Block struct {
		Header struct {
			Height string `json:"height"`
		} `json:"header"`
	} `json:"block"`
}

// GetLastBlock returns the last block height.
func (t *TerraSDK) GetLastBlock(ctx context.Context) (int64, error) {
	lastBlockURL := fmt.Sprintf("%s/cosmos/base/tendermint/v1beta1/blocks/latest", t.url)
	req, err := http.NewRequest(http.MethodGet, lastBlockURL, nil)
	if err != nil {
		return 0, err
	}
	req.Header.Add("Content-Type", "application/json")

	t.rl.Take()

	res, err := t.client.Do(req)
	if err != nil {
		return 0, err
	}
	defer res.Body.Close()

	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return 0, err
	}

	var response LastBlockResponse
	err = json.Unmarshal(body, &response)
	if err != nil {
		return 0, err
	}

	lastBlockHeight, err := strconv.ParseInt(response.Block.Header.Height, 10, 64)
	if err != nil {
		return 0, err
	}

	return lastBlockHeight, nil
}

type TxByBlockResponse struct {
	Limit      int  `json:"limit"`
	NextOffset *int `json:"next"`
	Txs        []Tx `json:"txs"`
}

type Tx struct {
	ID int `json:"id"`
	Tx struct {
		Type  string `json:"type"`
		Value struct {
			Fee struct {
				Gas    string `json:"gas"`
				Amount []struct {
					Denom  string `json:"denom"`
					Amount string `json:"amount"`
				} `json:"amount"`
			} `json:"fee"`
			Msg []struct {
				Type  string `json:"type"`
				Value struct {
					Coins      []any  `json:"coins"`
					Sender     string `json:"sender"`
					Contract   string `json:"contract"`
					ExecuteMsg struct {
						SubmitVaa struct {
							Data []byte `json:"data"`
						} `json:"submit_vaa"`
					} `json:"execute_msg"`
				} `json:"value"`
			} `json:"msg"`
			Memo       string `json:"memo"`
			Signatures []struct {
				PubKey struct {
					Type  string `json:"type"`
					Value string `json:"value"`
				} `json:"pub_key"`
				Signature string `json:"signature"`
			} `json:"signatures"`
			TimeoutHeight string `json:"timeout_height"`
		} `json:"value"`
	} `json:"tx"`
	Logs []struct {
		Log struct {
			Tax string `json:"tax"`
		} `json:"log"`
		Events []struct {
			Type       string `json:"type"`
			Attributes []struct {
				Key   string `json:"key"`
				Value string `json:"value"`
			} `json:"attributes"`
		} `json:"events"`
		MsgIndex int `json:"msg_index"`
	} `json:"logs"`
	Code      int       `json:"code"`
	Height    string    `json:"height"`
	Txhash    string    `json:"txhash"`
	RawLog    string    `json:"raw_log"`
	GasUsed   string    `json:"gas_used"`
	Timestamp time.Time `json:"timestamp"`
	GasWanted string    `json:"gas_wanted"`
}

// GetTransactionsByBlockHeight returns the transactions for a given block height.
func (t *TerraSDK) GetTransactionsByBlockHeight(ctx context.Context, height int64, offset *int) (*TxByBlockResponse, error) {
	transactionsByBlockURL := fmt.Sprintf("%s/v1/txs", t.url)
	req, err := http.NewRequest(http.MethodGet, transactionsByBlockURL, nil)
	if err != nil {
		return nil, err
	}
	values := req.URL.Query()
	values.Add("block", strconv.FormatInt(height, 10))
	values.Add("limit", "100")
	if offset != nil {
		values.Add("offset", strconv.Itoa(*offset))
	}
	req.URL.RawQuery = values.Encode()

	req.Header.Add("Content-Type", "application/json")

	t.rl.Take()

	res, err := t.client.Do(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()

	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return nil, err
	}

	var response TxByBlockResponse
	err = json.Unmarshal(body, &response)
	if err != nil {
		return nil, err
	}

	return &response, nil
}