// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
// vespa test command
// Author: jonmv

package cmd

import (
	"bytes"
	"crypto/tls"
	"encoding/json"
	"fmt"
	"github.com/spf13/cobra"
	"github.com/vespa-engine/vespa/client/go/util"
	"github.com/vespa-engine/vespa/client/go/vespa"
	"io/ioutil"
	"math"
	"net/http"
	"net/url"
	"os"
	"path"
	"path/filepath"
	"strings"
	"time"
)

func init() {
	rootCmd.AddCommand(testCmd)
}

var testCmd = &cobra.Command{
	Use:   "test [tests directory or test file]",
	Short: "Run a test suite, or a single test",
	Long: `Run a test suite, or a single test

Runs all JSON test files in the specified directory (the working
directory by default), or the single JSON test file specified.

See https://cloud.vespa.ai/en/reference/testing.html for details.`,
	Example: `$ vespa test src/test/application/tests/system-test
$ vespa test src/test/application/tests/system-test/feed-and-query.json`,
	Args:              cobra.MaximumNArgs(1),
	DisableAutoGenTag: true,
	Run: func(cmd *cobra.Command, args []string) {
		target := getTarget()
		testPath := "."
		if len(args) > 0 {
			testPath = args[0]
		}
		if count, failed := runTests(testPath, target, false); len(failed) != 0 {
			fmt.Fprintf(stdout, "\nFailed %d of %d tests:\n", len(failed), count)
			for _, test := range failed {
				fmt.Fprintln(stdout, test)
			}
			exitFunc(3)
		} else {
			plural := "s"
			if count == 1 {
				plural = ""
			}
			fmt.Fprintf(stdout, "\n%d test%s completed successfully\n", count, plural)
		}
	},
}

func runTests(rootPath string, target vespa.Target, dryRun bool) (int, []string) {
	count := 0
	failed := make([]string, 0)
	if stat, err := os.Stat(rootPath); err != nil {
		fatalErrHint(err, "See https://cloud.vespa.ai/en/reference/testing")
	} else if stat.IsDir() {
		tests, err := ioutil.ReadDir(rootPath) // TODO: Use os.ReadDir when >= 1.16 is required.
		if err != nil {
			fatalErrHint(err, "See https://cloud.vespa.ai/en/reference/testing")
		}
		previousFailed := false
		for _, test := range tests {
			if !test.IsDir() && filepath.Ext(test.Name()) == ".json" {
				testPath := path.Join(rootPath, test.Name())
				if previousFailed {
					fmt.Fprintln(stdout, "")
					previousFailed = false
				}
				failure := runTest(testPath, target, dryRun)
				if failure != "" {
					failed = append(failed, failure)
					previousFailed = true
				}
				count++
			}
		}
	} else if strings.HasSuffix(stat.Name(), ".json") {
		failure := runTest(rootPath, target, dryRun)
		if failure != "" {
			failed = append(failed, failure)
		}
		count++
	}
	if count == 0 {
		fatalErrHint(fmt.Errorf("Failed to find any tests at %s", rootPath), "See https://cloud.vespa.ai/en/reference/testing")
	}
	return count, failed
}

// Runs the test at the given path, and returns the specified test name if the test fails
func runTest(testPath string, target vespa.Target, dryRun bool) string {
	var test test
	testBytes, err := ioutil.ReadFile(testPath)
	if err != nil {
		fatalErrHint(err, "See https://cloud.vespa.ai/en/reference/testing")
	}
	if err = json.Unmarshal(testBytes, &test); err != nil {
		fatalErrHint(err, fmt.Sprintf("Failed parsing test at %s", testPath), "See https://cloud.vespa.ai/en/reference/testing")
	}

	testName := test.Name
	if test.Name == "" {
		testName = filepath.Base(testPath)
	}
	if !dryRun {
		fmt.Fprintf(stdout, "Running %s:", testName)
	}

	defaultParameters, err := getParameters(test.Defaults.ParametersRaw, path.Dir(testPath))
	if err != nil {
		fatalErrHint(err, fmt.Sprintf("Invalid default parameters for %s", testName), "See https://cloud.vespa.ai/en/reference/testing")
	}

	if len(test.Steps) == 0 {
		fatalErrHint(fmt.Errorf("a test must have at least one step, but none were found in %s", testPath), "See https://cloud.vespa.ai/en/reference/testing")
	}
	for i, step := range test.Steps {
		stepName := step.Name
		if stepName == "" {
			stepName = fmt.Sprintf("step %d", i+1)
		}
		failure, longFailure, err := verify(step, path.Dir(testPath), test.Defaults.Cluster, defaultParameters, target, dryRun)
		if err != nil {
			fatalErr(err, fmt.Sprintf("Error in %s", stepName), "See https://cloud.vespa.ai/en/reference/testing")
		}
		if !dryRun {
			if failure != "" {
				fmt.Fprintf(stdout, " Failed %s:\n%s\n", stepName, longFailure)
				return fmt.Sprintf("%s: %s: %s", testName, stepName, failure)
			}
			if i == 0 {
				fmt.Fprintf(stdout, " ")
			}
			fmt.Fprint(stdout, ".")
		}
	}
	if !dryRun {
		fmt.Fprintln(stdout, " OK")
	}
	return ""
}

// Asserts specified response is obtained for request, or returns a failure message, or an error if this fails
func verify(step step, testsPath string, defaultCluster string, defaultParameters map[string]string, target vespa.Target, dryRun bool) (string, string, error) {
	requestBody, err := getBody(step.Request.BodyRaw, testsPath)
	if err != nil {
		return "", "", err
	}

	parameters, err := getParameters(step.Request.ParametersRaw, testsPath)
	if err != nil {
		return "", "", err
	}
	for name, value := range defaultParameters {
		if _, present := parameters[name]; !present {
			parameters[name] = value
		}
	}

	cluster := step.Request.Cluster
	if cluster == "" {
		cluster = defaultCluster
	}

	var service *vespa.Service
	if !dryRun {
		service, err = target.Service("query", 0, 0, cluster)
		if err != nil {
			return "", "", err
		}
	}

	method := step.Request.Method
	if method == "" {
		method = "GET"
	}

	requestUri := step.Request.URI
	if requestUri == "" {
		requestUri = "/search/"
	}
	requestUrl, err := url.ParseRequestURI(requestUri)
	if err != nil {
		return "", "", err
	}
	externalEndpoint := requestUrl.IsAbs()
	if !externalEndpoint {
		baseURL := "http://dummy/"
		if service != nil {
			baseURL = service.BaseURL
		}
		requestUrl, err = url.ParseRequestURI(baseURL + requestUri)
		if err != nil {
			return "", "", err
		}
	}
	query := requestUrl.Query()
	for name, value := range parameters {
		query.Add(name, value)
	}
	requestUrl.RawQuery = query.Encode()

	header := http.Header{}
	header.Add("Content-Type", "application/json") // TODO: Not guaranteed to be true ...

	request := &http.Request{
		URL:    requestUrl,
		Method: method,
		Header: header,
		Body:   ioutil.NopCloser(bytes.NewReader(requestBody)),
	}
	defer request.Body.Close()

	statusCode := step.Response.Code
	if statusCode == 0 {
		statusCode = 200
	}

	responseBodySpecBytes, err := getBody(step.Response.BodyRaw, testsPath)
	if err != nil {
		return "", "", err
	}
	var responseBodySpec interface{}
	if responseBodySpecBytes != nil {
		err = json.Unmarshal(responseBodySpecBytes, &responseBodySpec)
		if err != nil {
			return "", "", fmt.Errorf("invalid response body spec: %w", err)
		}
	}

	if dryRun {
		return "", "", nil
	}

	var response *http.Response
	if externalEndpoint {
		util.ActiveHttpClient.UseCertificate([]tls.Certificate{})
		response, err = util.ActiveHttpClient.Do(request, 60*time.Second)
	} else {
		response, err = service.Do(request, 600*time.Second) // Vespa should provide a response within the given request timeout
	}
	if err != nil {
		return "", "", err
	}
	defer response.Body.Close()

	if statusCode != response.StatusCode {
		failure := fmt.Sprintf("Unexpected status code: %d", response.StatusCode)
		return failure, fmt.Sprintf("%s\nExpected: %d\nActual response:\n%s", failure, statusCode, util.ReaderToJSON(response.Body)), nil
	}

	if responseBodySpec == nil {
		return "", "", nil
	}

	responseBodyBytes, err := ioutil.ReadAll(response.Body)
	if err != nil {
		return "", "", err
	}
	var responseBody interface{}
	err = json.Unmarshal(responseBodyBytes, &responseBody)
	if err != nil {
		return "", "", fmt.Errorf("got non-JSON response; %w:\n%s", err, string(responseBodyBytes))
	}

	failure, expected, err := compare(responseBodySpec, responseBody, "")
	if failure != "" {
		responsePretty, _ := json.MarshalIndent(responseBody, "", "  ")
		longFailure := failure
		if expected != "" {
			longFailure += "\n" + expected
		}
		longFailure += "\nActual response:\n" + string(responsePretty)
		return failure, longFailure, err
	}
	return "", "", err
}

func compare(expected interface{}, actual interface{}, path string) (string, string, error) {
	typeMatch := false
	valueMatch := false
	switch u := expected.(type) {
	case nil:
		typeMatch = actual == nil
		valueMatch = actual == nil
	case bool:
		v, ok := actual.(bool)
		typeMatch = ok
		valueMatch = ok && u == v
	case float64:
		v, ok := actual.(float64)
		typeMatch = ok
		valueMatch = ok && math.Abs(u-v) < 1e-9
	case string:
		v, ok := actual.(string)
		typeMatch = ok
		valueMatch = ok && (u == v)
	case []interface{}:
		v, ok := actual.([]interface{})
		typeMatch = ok
		if ok {
			if len(u) == len(v) {
				for i, e := range u {
					failure, expected, err := compare(e, v[i], fmt.Sprintf("%s/%d", path, i))
					if failure != "" || err != nil {
						return failure, expected, err
					}
				}
				valueMatch = true
			} else {
				return fmt.Sprintf("Unexpected number of elements at %s: %d", path, len(v)), fmt.Sprintf("Expected: %d", len(u)), nil
			}
		}
	case map[string]interface{}:
		v, ok := actual.(map[string]interface{})
		typeMatch = ok
		if ok {
			for n, e := range u {
				childPath := fmt.Sprintf("%s/%s", path, strings.ReplaceAll(strings.ReplaceAll(n, "~", "~0"), "/", "~1"))
				f, ok := v[n]
				if !ok {
					return fmt.Sprintf("Missing expected field at %s", childPath), "", nil
				}
				failure, expected, err := compare(e, f, childPath)
				if failure != "" || err != nil {
					return failure, expected, err
				}
			}
			valueMatch = true
		}
	default:
		return "", "", fmt.Errorf("unexpected expected JSON type for value '%v'", expected)
	}

	if !valueMatch {
		if path == "" {
			path = "root"
		}
		mismatched := "type"
		if typeMatch {
			mismatched = "value"
		}
		expectedJson, _ := json.Marshal(expected)
		actualJson, _ := json.Marshal(actual)
		return fmt.Sprintf("Unexpected %s at %s: %s", mismatched, path, actualJson), fmt.Sprintf("Expected: %s", expectedJson), nil
	}
	return "", "", nil
}

func getParameters(parametersRaw []byte, testsPath string) (map[string]string, error) {
	if parametersRaw != nil {
		var parametersPath string
		if err := json.Unmarshal(parametersRaw, &parametersPath); err == nil {
			resolvedParametersPath := path.Join(testsPath, parametersPath)
			parametersRaw, err = ioutil.ReadFile(resolvedParametersPath)
			if err != nil {
				fatalErrHint(err, fmt.Sprintf("Failed to read request parameters file at '%s'", resolvedParametersPath), "See https://cloud.vespa.ai/en/reference/testing")
			}
		}
		var parameters map[string]string
		if err := json.Unmarshal(parametersRaw, &parameters); err != nil {
			return nil, fmt.Errorf("request parameters must be JSON with only string values: %w", err)
		}
		return parameters, nil
	}
	return make(map[string]string), nil
}

func getBody(bodyRaw []byte, testsPath string) ([]byte, error) {
	var bodyPath string
	if err := json.Unmarshal(bodyRaw, &bodyPath); err == nil {
		resolvedBodyPath := path.Join(testsPath, bodyPath)
		bodyRaw, err = ioutil.ReadFile(resolvedBodyPath)
		if err != nil {
			fatalErrHint(err, fmt.Sprintf("Failed to read body file at '%s'", resolvedBodyPath), "See https://cloud.vespa.ai/en/reference/testing")
		}
	}
	return bodyRaw, nil
}

type test struct {
	Name     string   `json:"name"`
	Defaults defaults `json:"defaults"`
	Steps    []step   `json:"steps"`
}

type defaults struct {
	Cluster       string          `json:"cluster"`
	ParametersRaw json.RawMessage `json:"parameters"`
}

type step struct {
	Name     string   `json:"name"`
	Request  request  `json:"request"`
	Response response `json:"response"`
}

type request struct {
	Cluster       string          `json:"cluster"`
	Method        string          `json:"method"`
	URI           string          `json:"uri"`
	ParametersRaw json.RawMessage `json:"parameters"`
	BodyRaw       json.RawMessage `json:"body"`
}

type response struct {
	Code    int             `json:"code"`
	BodyRaw json.RawMessage `json:"body"`
}