package api

import (
	"bytes"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"net/http"

	"git.sigsum.org/sigsum-lib-go/pkg/requests"
	"git.sigsum.org/sigsum-lib-go/pkg/types"
)

type NetworkClient struct {
	http.Client
	LogURL string
}

func NewNetworkClient(httpClient http.Client, logURL string) *NetworkClient {
	return &NetworkClient{
		Client: httpClient,
		LogURL: logURL,
	}
}

func (c *NetworkClient) GetToCosignTreeHead() (*types.SignedTreeHead, error) {
	return nil, fmt.Errorf("TODO")
}

func (c *NetworkClient) GetCosignedTreeHead() (*types.CosignedTreeHead, error) {
	rsp, err := c.get(types.EndpointGetTreeHeadCosigned.Path(c.LogURL))
	if err != nil {
		return nil, fmt.Errorf("client: HTTP %d: %s", rsp.StatusCode, errorMessage(rsp.Body))
	}

	defer rsp.Body.Close()
	if rsp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("client: HTTP %d: %s", rsp.StatusCode, errorMessage(rsp.Body))
	}

	var cth types.CosignedTreeHead
	if err := cth.FromASCII(rsp.Body); err != nil {
		return nil, fmt.Errorf("client: HTTP %d: %s", rsp.StatusCode, errorMessage(rsp.Body))
	}
	return &cth, nil
}

func (c *NetworkClient) GetInclusionProof(treeSize uint64, leafHash *types.Hash) (*types.InclusionProof, error) {
	data := requests.InclusionProof{
		TreeSize: treeSize,
		LeafHash: *leafHash,
	}
	buf := bytes.NewBuffer(nil)
	if err := data.ToASCII(buf); err != nil {
		return nil, fmt.Errorf("client: invalid request data: %v", err)
	}

	rsp, err := c.post(types.EndpointGetInclusionProof.Path(c.LogURL), buf)
	if err != nil {
		return nil, fmt.Errorf("client: invalid proof request: %v", err)
	}

	defer rsp.Body.Close()
	if rsp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("client: HTTP %d: %s", rsp.StatusCode, errorMessage(rsp.Body))
	}
	var proof types.InclusionProof
	if err := proof.FromASCII(rsp.Body, treeSize); err != nil {
		return nil, fmt.Errorf("client: failed parsing response: %v", err)
	}

	return &proof, nil
}

func (c *NetworkClient) GetConsistencyProof(oldSize, newSize uint64) (*types.ConsistencyProof, error) {
	return nil, fmt.Errorf("TODO")
}

func (c *NetworkClient) GetLeaves(startSize, endSize uint64) (*types.Leaves, error) {
	return nil, fmt.Errorf("TODO")
}

func (c *NetworkClient) AddLeaf(leaf *requests.Leaf) error {
	buf := bytes.NewBuffer(nil)
	if err := leaf.ToASCII(buf); err != nil {
		return fmt.Errorf("client: invalid request data: %v", err)
	}

	rsp, err := c.post(types.EndpointAddLeaf.Path(c.LogURL), buf)
	if err != nil {
		return fmt.Errorf("client: HTTP %d: %s", rsp.StatusCode, errorMessage(rsp.Body))
	}

	defer rsp.Body.Close()
	if rsp.StatusCode != http.StatusOK {
		return fmt.Errorf("client: HTTP %d: %s", rsp.StatusCode, errorMessage(rsp.Body))
	}
	return nil
}

func (c *NetworkClient) AddCosignature(*requests.Cosignature) error {
	return fmt.Errorf("TODO")
}

func (c *NetworkClient) get(url string) (*http.Response, error) {
	log.Printf("GET %s", url)
	return c.Get(url)
}

func (c *NetworkClient) post(url string, buf *bytes.Buffer) (*http.Response, error) {
	req, err := http.NewRequest("POST", url, buf)
	if err != nil {
		return nil, fmt.Errorf("client: invalid leaf request: %v", err)
	}

	log.Printf("POST %s", url)
	return c.Do(req)
}

func errorMessage(r io.Reader) string {
	b, _ := ioutil.ReadAll(r)
	return string(b)

	// TODO: the below doesn't work because log error messages are malformed
	//msg := struct {
	//	Message string `ascii:"Error"`
	//}{}
	//if err := ascii.StdEncoding.Deserialize(r, &msg); err != nil {
	//	return fmt.Sprintf("malformed error message: %v", err)
	//}
	//return msg.Message
}