package cmd

import (
	"context"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"regexp"
	"runtime/pprof"
	"strings"
	"time"

	homedir "github.com/mitchellh/go-homedir"
	"github.com/pkg/errors"
	"github.com/rs/zerolog"
	"github.com/rs/zerolog/log"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
	"github.com/vektra/mockery/v2/pkg"
	"github.com/vektra/mockery/v2/pkg/config"
	"github.com/vektra/mockery/v2/pkg/logging"
	"golang.org/x/crypto/ssh/terminal"
	"golang.org/x/tools/go/packages"
)

var (
	cfgFile = ""
	rootCmd = &cobra.Command{
		Use:   "mockery",
		Short: "Generate mock objects for your Golang interfaces",
		RunE: func(cmd *cobra.Command, args []string) error {
			r, err := GetRootAppFromViper(viper.GetViper())
			if err != nil {
				printStackTrace(err)
				return err
			}
			return r.Run()
		},
	}
)

type stackTracer interface {
	StackTrace() errors.StackTrace
}

func printStackTrace(e error) {
	fmt.Printf("%v\n", e)
	if err, ok := e.(stackTracer); ok {
		for _, f := range err.StackTrace() {
			fmt.Printf("%+s:%d\n", f, f)
		}
	}

}

// Execute executes the cobra CLI workflow
func Execute() {
	if err := rootCmd.Execute(); err != nil {
		//printStackTrace(err)
		os.Exit(1)
	}
}

func init() {
	cobra.OnInitialize(initConfig)

	pFlags := rootCmd.PersistentFlags()
	pFlags.StringVar(&cfgFile, "config", "", "config file to use")
	pFlags.String("name", "", "name or matching regular expression of interface to generate mock for")
	pFlags.Bool("print", false, "print the generated mock to stdout")
	pFlags.String("output", "./mocks", "directory to write mocks to")
	pFlags.String("outpkg", "mocks", "name of generated package")
	pFlags.String("packageprefix", "", "prefix for the generated package name, it is ignored if outpkg is also specified.")
	pFlags.String("dir", ".", "directory to search for interfaces")
	pFlags.BoolP("recursive", "r", false, "recurse search into sub-directories")
	pFlags.Bool("all", false, "generates mocks for all found interfaces in all sub-directories")
	pFlags.Bool("inpackage", false, "generate a mock that goes inside the original package")
	pFlags.Bool("testonly", false, "generate a mock in a _test.go file")
	pFlags.String("case", "camel", "name the mocked file using casing convention [camel, snake, underscore]")
	pFlags.String("note", "", "comment to insert into prologue of each generated file")
	pFlags.String("cpuprofile", "", "write cpu profile to file")
	pFlags.Bool("version", false, "prints the installed version of mockery")
	pFlags.Bool("quiet", false, `suppresses logger output (equivalent to --log-level="")`)
	pFlags.Bool("keeptree", false, "keep the tree structure of the original interface files into a different repository. Must be used with XX")
	pFlags.String("tags", "", "space-separated list of additional build tags to use")
	pFlags.String("filename", "", "name of generated file (only works with -name and no regex)")
	pFlags.String("structname", "", "name of generated struct (only works with -name and no regex)")
	pFlags.String("log-level", "info", "Level of logging")
	pFlags.String("srcpkg", "", "source pkg to search for interfaces")
	pFlags.BoolP("dry-run", "d", false, "Do a dry run, don't modify any files")
	pFlags.Bool("disable-version-string", false, "Do not insert the version string into the generated mock file.")
	pFlags.String("boilerplate-file", "", "File to read a boilerplate text from. Text should be a go block comment, i.e. /* ... */")
	pFlags.Bool("unroll-variadic", true, "For functions with variadic arguments, do not unroll the arguments into the underlying testify call. Instead, pass variadic slice as-is.")
	pFlags.Bool("exported", false, "Generates public mocks for private interfaces.")

	viper.BindPFlags(pFlags)
}

func initConfig() {
	if cfgFile != "" {
		// Use config file from the flag.
		viper.SetConfigFile(cfgFile)
	} else {
		// Find home directory.
		home, err := homedir.Dir()
		if err != nil {
			log.Fatal().Err(err).Msgf("Failed to find homedir")
		}

		// Search config in home directory with name ".cobra" (without extension).
		viper.AddConfigPath(".")
		viper.AddConfigPath(home)
		viper.SetConfigName(".mockery")
	}

	viper.SetEnvPrefix("mockery")
	viper.AutomaticEnv()

	// Note we purposely ignore the error. Don't care if we can't find a config file.
	if err := viper.ReadInConfig(); err == nil {
		fmt.Fprintf(os.Stderr, "Using config file: %s\n", viper.ConfigFileUsed())
	}
}

const regexMetadataChars = "\\.+*?()|[]{}^$"

type RootApp struct {
	config.Config
}

func GetRootAppFromViper(v *viper.Viper) (*RootApp, error) {
	r := &RootApp{}
	if err := v.UnmarshalExact(&r.Config); err != nil {
		return nil, errors.Wrapf(err, "failed to get config")
	}
	return r, nil
}

func (r *RootApp) Run() error {
	var recursive bool
	var filter *regexp.Regexp
	var err error
	var limitOne bool

	if r.Quiet {
		// if "quiet" flag is set, disable logging
		r.Config.LogLevel = ""
	}

	log, err := getLogger(r.Config.LogLevel)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Failed to initialize logger: %v\n", err)
		return err
	}
	log = log.With().Bool(logging.LogKeyDryRun, r.Config.DryRun).Logger()
	log.Info().Msgf("Starting mockery")
	ctx := log.WithContext(context.Background())

	if r.Config.Version {
		fmt.Println(config.GetSemverInfo())
		return nil
	} else if r.Config.Name != "" && r.Config.All {
		log.Fatal().Msgf("Specify --name or --all, but not both")
	} else if (r.Config.FileName != "" || r.Config.StructName != "") && r.Config.All {
		log.Fatal().Msgf("Cannot specify --filename or --structname with --all")
	} else if r.Config.Dir != "" && r.Config.Dir != "." && r.Config.SrcPkg != "" {
		log.Fatal().Msgf("Specify -dir or -srcpkg, but not both")
	} else if r.Config.Name != "" {
		recursive = r.Config.Recursive
		if strings.ContainsAny(r.Config.Name, regexMetadataChars) {
			if filter, err = regexp.Compile(r.Config.Name); err != nil {
				log.Fatal().Err(err).Msgf("Invalid regular expression provided to -name")
			} else if r.Config.FileName != "" || r.Config.StructName != "" {
				log.Fatal().Msgf("Cannot specify --filename or --structname with regex in --name")
			}
		} else {
			filter = regexp.MustCompile(fmt.Sprintf("^%s$", r.Config.Name))
			limitOne = true
		}
	} else if r.Config.All {
		recursive = true
		filter = regexp.MustCompile(".*")
	} else {
		log.Fatal().Msgf("Use --name to specify the name of the interface or --all for all interfaces found")
	}

	if r.Config.Profile != "" {
		f, err := os.Create(r.Config.Profile)
		if err != nil {
			return errors.Wrapf(err, "Failed to create profile file")
		}

		pprof.StartCPUProfile(f)
		defer pprof.StopCPUProfile()
	}

	var osp pkg.OutputStreamProvider
	if r.Config.Print {
		osp = &pkg.StdoutStreamProvider{}
	} else {
		osp = &pkg.FileOutputStreamProvider{
			Config:                    r.Config,
			BaseDir:                   r.Config.Output,
			InPackage:                 r.Config.InPackage,
			TestOnly:                  r.Config.TestOnly,
			Case:                      r.Config.Case,
			KeepTree:                  r.Config.KeepTree,
			KeepTreeOriginalDirectory: r.Config.Dir,
			FileName:                  r.Config.FileName,
		}
	}

	baseDir := r.Config.Dir

	if r.Config.SrcPkg != "" {
		pkgs, err := packages.Load(&packages.Config{
			Mode: packages.NeedFiles,
		}, r.Config.SrcPkg)
		if err != nil || len(pkgs) == 0 {
			log.Fatal().Err(err).Msgf("Failed to load package %s", r.Config.SrcPkg)
		}

		// NOTE: we only pass one package name (config.SrcPkg) to packages.Load
		// it should return one package at most
		pkg := pkgs[0]

		if pkg.Errors != nil {
			log.Fatal().Err(pkg.Errors[0]).Msgf("Failed to load package %s", r.Config.SrcPkg)
		}

		if len(pkg.GoFiles) == 0 {
			log.Fatal().Msgf("No go files in package %s", r.Config.SrcPkg)
		}
		baseDir = filepath.Dir(pkg.GoFiles[0])
	}

	var boilerplate string
	if r.Config.BoilerplateFile != "" {
		data, err := ioutil.ReadFile(r.Config.BoilerplateFile)
		if err != nil {
			log.Fatal().Msgf("Failed to read boilerplate file %s: %v", r.Config.BoilerplateFile, err)
		}
		boilerplate = string(data)
	}

	visitor := &pkg.GeneratorVisitor{
		Config:            r.Config,
		InPackage:         r.Config.InPackage,
		Note:              r.Config.Note,
		Boilerplate:       boilerplate,
		Osp:               osp,
		PackageName:       r.Config.Outpkg,
		PackageNamePrefix: r.Config.Packageprefix,
		StructName:        r.Config.StructName,
	}

	walker := pkg.Walker{
		Config:    r.Config,
		BaseDir:   baseDir,
		Recursive: recursive,
		Filter:    filter,
		LimitOne:  limitOne,
		BuildTags: strings.Split(r.Config.BuildTags, " "),
	}

	generated := walker.Walk(ctx, visitor)

	if r.Config.Name != "" && !generated {
		log.Fatal().Msgf("Unable to find '%s' in any go files under this path", r.Config.Name)
	}
	return nil
}

type timeHook struct{}

func (t timeHook) Run(e *zerolog.Event, level zerolog.Level, msg string) {
	e.Time("time", time.Now())
}

func getLogger(levelStr string) (zerolog.Logger, error) {
	level, err := zerolog.ParseLevel(levelStr)
	if err != nil {
		return zerolog.Logger{}, errors.Wrapf(err, "Couldn't parse log level")
	}
	out := os.Stderr
	writer := zerolog.ConsoleWriter{
		Out:        out,
		TimeFormat: time.RFC822,
	}
	if !terminal.IsTerminal(int(out.Fd())) {
		writer.NoColor = true
	}
	log := zerolog.New(writer).
		Hook(timeHook{}).
		Level(level).
		With().
		Str("version", config.GetSemverInfo()).
		Logger()

	return log, nil
}