package api

import (
	"context"
	"fmt"
	"io"
	"net/http"

	"github.com/hashicorp/vault/sdk/helper/consts"
)

// RaftJoinResponse represents the response of the raft join API
type RaftJoinResponse struct {
	Joined bool `json:"joined"`
}

// RaftJoinRequest represents the parameters consumed by the raft join API
type RaftJoinRequest struct {
	LeaderAPIAddr    string `json:"leader_api_addr"`
	LeaderCACert     string `json:"leader_ca_cert"`
	LeaderClientCert string `json:"leader_client_cert"`
	LeaderClientKey  string `json:"leader_client_key"`
	Retry            bool   `json:"retry"`
	NonVoter         bool   `json:"non_voter"`
}

// RaftJoin adds the node from which this call is invoked from to the raft
// cluster represented by the leader address in the parameter.
func (c *Sys) RaftJoin(opts *RaftJoinRequest) (*RaftJoinResponse, error) {
	r := c.c.NewRequest("POST", "/v1/sys/storage/raft/join")

	if err := r.SetJSONBody(opts); err != nil {
		return nil, err
	}

	ctx, cancelFunc := context.WithCancel(context.Background())
	defer cancelFunc()
	resp, err := c.c.RawRequestWithContext(ctx, r)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	var result RaftJoinResponse
	err = resp.DecodeJSON(&result)
	return &result, err
}

// RaftSnapshot invokes the API that takes the snapshot of the raft cluster and
// writes it to the supplied io.Writer.
func (c *Sys) RaftSnapshot(snapWriter io.Writer) error {
	r := c.c.NewRequest("GET", "/v1/sys/storage/raft/snapshot")
	r.URL.RawQuery = r.Params.Encode()

	req, err := http.NewRequest(http.MethodGet, r.URL.RequestURI(), nil)
	if err != nil {
		return err
	}

	req.URL.User = r.URL.User
	req.URL.Scheme = r.URL.Scheme
	req.URL.Host = r.URL.Host
	req.Host = r.URL.Host

	if r.Headers != nil {
		for header, vals := range r.Headers {
			for _, val := range vals {
				req.Header.Add(header, val)
			}
		}
	}

	if len(r.ClientToken) != 0 {
		req.Header.Set(consts.AuthHeaderName, r.ClientToken)
	}

	if len(r.WrapTTL) != 0 {
		req.Header.Set("X-Vault-Wrap-TTL", r.WrapTTL)
	}

	if len(r.MFAHeaderVals) != 0 {
		for _, mfaHeaderVal := range r.MFAHeaderVals {
			req.Header.Add("X-Vault-MFA", mfaHeaderVal)
		}
	}

	if r.PolicyOverride {
		req.Header.Set("X-Vault-Policy-Override", "true")
	}

	// Avoiding the use of RawRequestWithContext which reads the response body
	// to determine if the body contains error message.
	var result *Response
	resp, err := c.c.config.HttpClient.Do(req)
	if err != nil {
		return err
	}

	if resp == nil {
		return nil
	}

	// Check for a redirect, only allowing for a single redirect
	if resp.StatusCode == 301 || resp.StatusCode == 302 || resp.StatusCode == 307 {
		// Parse the updated location
		respLoc, err := resp.Location()
		if err != nil {
			return err
		}

		// Ensure a protocol downgrade doesn't happen
		if req.URL.Scheme == "https" && respLoc.Scheme != "https" {
			return fmt.Errorf("redirect would cause protocol downgrade")
		}

		// Update the request
		req.URL = respLoc

		// Retry the request
		resp, err = c.c.config.HttpClient.Do(req)
		if err != nil {
			return err
		}
	}

	result = &Response{Response: resp}
	if err := result.Error(); err != nil {
		return err
	}

	_, err = io.Copy(snapWriter, resp.Body)
	if err != nil {
		return err
	}

	return nil
}

// RaftSnapshotRestore reads the snapshot from the io.Reader and installs that
// snapshot, returning the cluster to the state defined by it.
func (c *Sys) RaftSnapshotRestore(snapReader io.Reader, force bool) error {
	path := "/v1/sys/storage/raft/snapshot"
	if force {
		path = "/v1/sys/storage/raft/snapshot-force"
	}
	r := c.c.NewRequest("POST", path)

	r.Body = snapReader

	ctx, cancelFunc := context.WithCancel(context.Background())
	defer cancelFunc()
	resp, err := c.c.RawRequestWithContext(ctx, r)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	return nil
}