// Copyright 2019 Sorint.lab
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied
// See the License for the specific language governing permissions and
// limitations under the License.

package api

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"net/url"
	"strconv"
	"strings"

	"github.com/sorintlab/agola/internal/services/types"

	"github.com/pkg/errors"
)

var jsonContent = http.Header{"content-type": []string{"application/json"}}

// Client represents a Gogs API client.
type Client struct {
	url    string
	client *http.Client
	token  string
}

// NewClient initializes and returns a API client.
func NewClient(url, token string) *Client {
	return &Client{
		url:    strings.TrimSuffix(url, "/"),
		client: &http.Client{},
		token:  token,
	}
}

// SetHTTPClient replaces default http.Client with user given one.
func (c *Client) SetHTTPClient(client *http.Client) {
	c.client = client
}

func (c *Client) doRequest(ctx context.Context, method, path string, query url.Values, header http.Header, ibody io.Reader) (*http.Response, error) {
	u, err := url.Parse(c.url + "/api/v1alpha" + path)
	if err != nil {
		return nil, err
	}
	u.RawQuery = query.Encode()

	req, err := http.NewRequest(method, u.String(), ibody)
	req = req.WithContext(ctx)
	if err != nil {
		return nil, err
	}

	req.Header.Set("Authorization", "token "+c.token)
	for k, v := range header {
		req.Header[k] = v
	}

	return c.client.Do(req)
}

func (c *Client) getResponse(ctx context.Context, method, path string, query url.Values, header http.Header, ibody io.Reader) (*http.Response, error) {
	resp, err := c.doRequest(ctx, method, path, query, header, ibody)
	if err != nil {
		return nil, err
	}

	if resp.StatusCode/100 != 2 {
		defer resp.Body.Close()
		data, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			return nil, err
		}

		if len(data) <= 1 {
			return resp, errors.New(resp.Status)
		}

		// TODO(sgotti) use a json error response

		return resp, errors.New(string(data))
	}

	return resp, nil
}

func (c *Client) getParsedResponse(ctx context.Context, method, path string, query url.Values, header http.Header, ibody io.Reader, obj interface{}) (*http.Response, error) {
	resp, err := c.getResponse(ctx, method, path, query, header, ibody)
	if err != nil {
		return resp, err
	}
	defer resp.Body.Close()

	d := json.NewDecoder(resp.Body)

	return resp, d.Decode(obj)
}

func (c *Client) GetProject(ctx context.Context, projectID string) (*types.Project, *http.Response, error) {
	project := new(types.Project)
	resp, err := c.getParsedResponse(ctx, "GET", fmt.Sprintf("/project/%s", projectID), nil, jsonContent, nil, project)
	return project, resp, err
}

func (c *Client) GetProjects(ctx context.Context, start string, limit int, asc bool) (*GetProjectsResponse, *http.Response, error) {
	q := url.Values{}
	if start != "" {
		q.Add("start", start)
	}
	if limit > 0 {
		q.Add("limit", strconv.Itoa(limit))
	}
	if asc {
		q.Add("asc", "")
	}

	projects := new(GetProjectsResponse)
	resp, err := c.getParsedResponse(ctx, "GET", "/projects", q, jsonContent, nil, &projects)
	return projects, resp, err
}

func (c *Client) CreateProject(ctx context.Context, req *CreateProjectRequest) (*types.Project, *http.Response, error) {
	reqj, err := json.Marshal(req)
	if err != nil {
		return nil, nil, err
	}

	project := new(types.Project)
	resp, err := c.getParsedResponse(ctx, "PUT", "/projects", nil, jsonContent, bytes.NewReader(reqj), project)
	return project, resp, err
}

func (c *Client) DeleteProject(ctx context.Context, projectName string) (*http.Response, error) {
	return c.getResponse(ctx, "DELETE", fmt.Sprintf("/projects/%s", projectName), nil, jsonContent, nil)
}

func (c *Client) ReconfigProject(ctx context.Context, projectName string) (*http.Response, error) {
	return c.getResponse(ctx, "POST", fmt.Sprintf("/projects/%s/reconfig", projectName), nil, jsonContent, nil)
}

func (c *Client) GetUser(ctx context.Context, userID string) (*types.User, *http.Response, error) {
	user := new(types.User)
	resp, err := c.getParsedResponse(ctx, "GET", fmt.Sprintf("/user/%s", userID), nil, jsonContent, nil, user)
	return user, resp, err
}

func (c *Client) GetUsers(ctx context.Context, start string, limit int, asc bool) (*UsersResponse, *http.Response, error) {
	q := url.Values{}
	if start != "" {
		q.Add("start", start)
	}
	if limit > 0 {
		q.Add("limit", strconv.Itoa(limit))
	}
	if asc {
		q.Add("asc", "")
	}

	users := new(UsersResponse)
	resp, err := c.getParsedResponse(ctx, "GET", "/users", q, jsonContent, nil, &users)
	return users, resp, err
}

func (c *Client) CreateUser(ctx context.Context, req *CreateUserRequest) (*UserResponse, *http.Response, error) {
	reqj, err := json.Marshal(req)
	if err != nil {
		return nil, nil, err
	}

	user := new(UserResponse)
	resp, err := c.getParsedResponse(ctx, "PUT", "/users", nil, jsonContent, bytes.NewReader(reqj), user)
	return user, resp, err
}

func (c *Client) DeleteUser(ctx context.Context, userName string) (*http.Response, error) {
	return c.getResponse(ctx, "DELETE", fmt.Sprintf("/users/%s", userName), nil, jsonContent, nil)
}

func (c *Client) CreateUserLA(ctx context.Context, userName string, req *CreateUserLARequest) (*CreateUserLAResponse, *http.Response, error) {
	reqj, err := json.Marshal(req)
	if err != nil {
		return nil, nil, err
	}

	la := new(CreateUserLAResponse)
	resp, err := c.getParsedResponse(ctx, "PUT", fmt.Sprintf("/users/%s/linkedaccounts", userName), nil, jsonContent, bytes.NewReader(reqj), la)
	return la, resp, err
}

func (c *Client) DeleteUserLA(ctx context.Context, userName, laID string) (*http.Response, error) {
	return c.getResponse(ctx, "DELETE", fmt.Sprintf("/users/%s/linkedaccounts/%s", userName, laID), nil, jsonContent, nil)
}

func (c *Client) CreateUserToken(ctx context.Context, userName string, req *CreateUserTokenRequest) (*CreateUserTokenResponse, *http.Response, error) {
	reqj, err := json.Marshal(req)
	if err != nil {
		return nil, nil, err
	}

	tresp := new(CreateUserTokenResponse)
	resp, err := c.getParsedResponse(ctx, "PUT", fmt.Sprintf("/users/%s/tokens", userName), nil, jsonContent, bytes.NewReader(reqj), tresp)
	return tresp, resp, err
}

func (c *Client) GetRun(ctx context.Context, runID string) (*RunResponse, *http.Response, error) {
	run := new(RunResponse)
	resp, err := c.getParsedResponse(ctx, "GET", fmt.Sprintf("/run/%s", runID), nil, jsonContent, nil, run)
	return run, resp, err
}

func (c *Client) GetRuns(ctx context.Context, phaseFilter, groups, runGroups []string, start string, limit int, asc bool) (*GetRunsResponse, *http.Response, error) {
	q := url.Values{}
	for _, phase := range phaseFilter {
		q.Add("phase", phase)
	}
	for _, group := range groups {
		q.Add("group", group)
	}
	for _, runGroup := range runGroups {
		q.Add("rungroup", runGroup)
	}
	if start != "" {
		q.Add("start", start)
	}
	if limit > 0 {
		q.Add("limit", strconv.Itoa(limit))
	}
	if asc {
		q.Add("asc", "")
	}

	getRunsResponse := new(GetRunsResponse)
	resp, err := c.getParsedResponse(ctx, "GET", "/runs", q, jsonContent, nil, getRunsResponse)
	return getRunsResponse, resp, err
}

func (c *Client) GetRemoteSource(ctx context.Context, rsID string) (*RemoteSourceResponse, *http.Response, error) {
	rs := new(RemoteSourceResponse)
	resp, err := c.getParsedResponse(ctx, "GET", fmt.Sprintf("/remotesource/%s", rsID), nil, jsonContent, nil, rs)
	return rs, resp, err
}

func (c *Client) GetRemoteSources(ctx context.Context, start string, limit int, asc bool) (*RemoteSourcesResponse, *http.Response, error) {
	q := url.Values{}
	if start != "" {
		q.Add("start", start)
	}
	if limit > 0 {
		q.Add("limit", strconv.Itoa(limit))
	}
	if asc {
		q.Add("asc", "")
	}

	rss := new(RemoteSourcesResponse)
	resp, err := c.getParsedResponse(ctx, "GET", "/remotesources", q, jsonContent, nil, &rss)
	return rss, resp, err
}

func (c *Client) CreateRemoteSource(ctx context.Context, req *CreateRemoteSourceRequest) (*types.RemoteSource, *http.Response, error) {
	uj, err := json.Marshal(req)
	if err != nil {
		return nil, nil, err
	}

	rs := new(types.RemoteSource)
	resp, err := c.getParsedResponse(ctx, "PUT", "/remotesources", nil, jsonContent, bytes.NewReader(uj), rs)
	return rs, resp, err
}

func (c *Client) DeleteRemoteSource(ctx context.Context, name string) (*http.Response, error) {
	return c.getResponse(ctx, "DELETE", fmt.Sprintf("/remotesources/%s", name), nil, jsonContent, nil)
}