package view

import (
	"context"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"

	"github.com/derailed/k9s/internal"
	"github.com/derailed/k9s/internal/config"
	"github.com/derailed/k9s/internal/dao"
	"github.com/derailed/k9s/internal/perf"
	"github.com/derailed/k9s/internal/render"
	"github.com/derailed/k9s/internal/ui"
	"github.com/gdamore/tcell"
	"github.com/rs/zerolog/log"
)

const (
	benchTitle  = "Benchmarks"
	resultTitle = "Benchmark Results"
)

// Benchmark represents a service benchmark results view.
type Benchmark struct {
	ResourceViewer

	details *Details
}

// NewBench returns a new viewer.
func NewBenchmark(gvr dao.GVR) ResourceViewer {
	b := Benchmark{
		ResourceViewer: NewBrowser(gvr),
		details:        NewDetails(resultTitle),
	}
	b.GetTable().SetBorderFocusColor(tcell.ColorSeaGreen)
	b.GetTable().SetSelectedStyle(tcell.ColorWhite, tcell.ColorSeaGreen, tcell.AttrNone)
	b.GetTable().SetColorerFn(render.Benchmark{}.ColorerFunc())
	b.GetTable().SetSortCol(b.GetTable().NameColIndex()+7, 0, true)
	b.SetContextFn(b.benchContext)
	b.GetTable().SetEnterFn(b.viewBench)

	return &b
}

func (b *Benchmark) benchContext(ctx context.Context) context.Context {
	return context.WithValue(ctx, internal.KeyDir, benchDir(b.App().Config))
}

// BOZO!!
// // Start runs the refresh loop
// func (b *Bench) Start() {
// 	log.Debug().Msgf(">>>> Bench START")
// 	var ctx context.Context

// 	ctx, b.cancelFn = context.WithCancel(context.Background())
// 	if err := b.watchBenchDir(ctx); err != nil {
// 		b.App().Flash().Errf("Unable to watch benchmarks directory %s", err)
// 	}
// }

func (b *Benchmark) viewBench(app *App, ns, res, path string) {
	log.Debug().Msgf("VIEWBENCH %q -- %q -- %q", ns, res, path)
	data, err := readBenchFile(app.Config, b.benchFile())
	if err != nil {
		b.App().Flash().Errf("Unable to load bench file %s", err)
		return
	}

	b.details.SetText(data)
	b.details.SetSubject(fileToSubject(path))
	b.App().inject(b.details)

	return
}

func fileToSubject(path string) string {
	tokens := strings.Split(path, "/")
	log.Debug().Msgf("TOKENS %v", tokens)
	ee := strings.Split(tokens[len(tokens)-1], "_")
	return ee[0] + "/" + ee[1]
}

func (b *Benchmark) deleteCmd(evt *tcell.EventKey) *tcell.EventKey {
	if !b.GetTable().RowSelected() {
		return nil
	}

	sel, file := b.GetTable().GetSelectedItem(), b.benchFile()
	dir := filepath.Join(perf.K9sBenchDir, b.App().Config.K9s.CurrentCluster)
	showModal(b.App().Content.Pages, fmt.Sprintf("Delete benchmark `%s?", file), func() {
		if err := os.Remove(filepath.Join(dir, file)); err != nil {
			b.App().Flash().Errf("Unable to delete file %s", err)
			return
		}
		b.App().Flash().Infof("Benchmark %s deleted!", sel)
	})

	return nil
}

func (b *Benchmark) benchFile() string {
	r := b.GetTable().GetSelectedRowIndex()
	return ui.TrimCell(b.GetTable().SelectTable, r, 7)
}

// BOZO!!
// func (b *Benchmark) watchBenchDir(ctx context.Context) error {
// 	w, err := fsnotify.NewWatcher()
// 	if err != nil {
// 		return err
// 	}

// 	go func() {
// 		for {
// 			select {
// 			case evt := <-w.Events:
// 				log.Debug().Msgf("Bench event %#v", evt)
// 				b.App().QueueUpdateDraw(func() {
// 					b.Refresh()
// 				})
// 			case err := <-w.Errors:
// 				log.Info().Err(err).Msg("Dir Watcher failed")
// 				return
// 			case <-ctx.Done():
// 				log.Debug().Msg("!!!! FS WATCHER DONE!!")
// 				if err := w.Close(); err != nil {
// 					log.Error().Err(err).Msg("Closing bench watched")
// 				}
// 				return
// 			}
// 		}
// 	}()

// 	return w.Add(benchDir(b.App().Config))
// }

// ----------------------------------------------------------------------------
// Helpers...

func benchDir(cfg *config.Config) string {
	return filepath.Join(perf.K9sBenchDir, cfg.K9s.CurrentCluster)
}

func loadBenchDir(cfg *config.Config) ([]os.FileInfo, error) {
	return ioutil.ReadDir(benchDir(cfg))
}

func readBenchFile(cfg *config.Config, n string) (string, error) {
	data, err := ioutil.ReadFile(filepath.Join(benchDir(cfg), n))
	if err != nil {
		return "", err
	}
	return string(data), nil
}