package parser

import (
	"fmt"
	"os"
	"path/filepath"
	"sort"
	"strings"

	log "github.com/sirupsen/logrus"

	"github.com/crowdsecurity/grokky"

	"github.com/crowdsecurity/crowdsec/pkg/csconfig"
	"github.com/crowdsecurity/crowdsec/pkg/cwhub"
	"github.com/crowdsecurity/crowdsec/pkg/fflag"
)

type UnixParserCtx struct {
	Grok       grokky.Host
	Stages     []string
	Profiling  bool
	DataFolder string
}

type Parsers struct {
	Ctx             *UnixParserCtx
	Povfwctx        *UnixParserCtx
	StageFiles      []Stagefile
	PovfwStageFiles []Stagefile
	Nodes           []Node
	Povfwnodes      []Node
	EnricherCtx     EnricherCtx
}

func Init(c map[string]interface{}) (*UnixParserCtx, error) {
	r := UnixParserCtx{}
	r.Grok = grokky.NewBase()
	r.Grok.UseRe2 = fflag.Re2GrokSupport.IsEnabled()
	files, err := os.ReadDir(c["patterns"].(string))
	if err != nil {
		return nil, err
	}
	r.DataFolder = c["data"].(string)
	for _, f := range files {
		if strings.Contains(f.Name(), ".") {
			continue
		}
		if err := r.Grok.AddFromFile(filepath.Join(c["patterns"].(string), f.Name())); err != nil {
			log.Errorf("failed to load pattern %s : %v", f.Name(), err)
			return nil, err
		}
	}
	log.Debugf("Loaded %d pattern files", len(files))
	return &r, nil
}

// Return new parsers
// nodes and povfwnodes are already initialized in parser.LoadStages
func NewParsers(hub *cwhub.Hub) *Parsers {
	parsers := &Parsers{
		Ctx:             &UnixParserCtx{},
		Povfwctx:        &UnixParserCtx{},
		StageFiles:      make([]Stagefile, 0),
		PovfwStageFiles: make([]Stagefile, 0),
	}

	for _, itemType := range []string{cwhub.PARSERS, cwhub.POSTOVERFLOWS} {
		for _, hubParserItem := range hub.GetItemMap(itemType) {
			if hubParserItem.State.Installed {
				stagefile := Stagefile{
					Filename: hubParserItem.State.LocalPath,
					Stage:    hubParserItem.Stage,
				}
				if itemType == cwhub.PARSERS {
					parsers.StageFiles = append(parsers.StageFiles, stagefile)
				}
				if itemType == cwhub.POSTOVERFLOWS {
					parsers.PovfwStageFiles = append(parsers.PovfwStageFiles, stagefile)
				}
			}
		}
	}
	if parsers.StageFiles != nil {
		sort.Slice(parsers.StageFiles, func(i, j int) bool {
			return parsers.StageFiles[i].Filename < parsers.StageFiles[j].Filename
		})
	}
	if parsers.PovfwStageFiles != nil {
		sort.Slice(parsers.PovfwStageFiles, func(i, j int) bool {
			return parsers.PovfwStageFiles[i].Filename < parsers.PovfwStageFiles[j].Filename
		})
	}

	return parsers
}

func LoadParsers(cConfig *csconfig.Config, parsers *Parsers) (*Parsers, error) {
	var err error

	patternsDir := cConfig.ConfigPaths.PatternDir
	log.Infof("Loading grok library %s", patternsDir)
	/* load base regexps for two grok parsers */
	parsers.Ctx, err = Init(map[string]interface{}{"patterns": patternsDir,
		"data": cConfig.ConfigPaths.DataDir})
	if err != nil {
		return parsers, fmt.Errorf("failed to load parser patterns : %v", err)
	}
	parsers.Povfwctx, err = Init(map[string]interface{}{"patterns": patternsDir,
		"data": cConfig.ConfigPaths.DataDir})
	if err != nil {
		return parsers, fmt.Errorf("failed to load postovflw parser patterns : %v", err)
	}

	/*
		Load enrichers
	*/
	log.Infof("Loading enrich plugins")

	parsers.EnricherCtx, err = Loadplugin(cConfig.ConfigPaths.DataDir)
	if err != nil {
		return parsers, fmt.Errorf("failed to load enrich plugin : %v", err)
	}

	/*
	 Load the actual parsers
	*/

	log.Infof("Loading parsers from %d files", len(parsers.StageFiles))

	parsers.Nodes, err = LoadStages(parsers.StageFiles, parsers.Ctx, parsers.EnricherCtx)
	if err != nil {
		return parsers, fmt.Errorf("failed to load parser config : %v", err)
	}

	if len(parsers.PovfwStageFiles) > 0 {
		log.Infof("Loading postoverflow parsers")
		parsers.Povfwnodes, err = LoadStages(parsers.PovfwStageFiles, parsers.Povfwctx, parsers.EnricherCtx)
	} else {
		log.Infof("No postoverflow parsers to load")
		parsers.Povfwnodes = []Node{}
	}

	if err != nil {
		return parsers, fmt.Errorf("failed to load postoverflow config : %v", err)
	}

	if cConfig.Prometheus != nil && cConfig.Prometheus.Enabled {
		parsers.Ctx.Profiling = true
		parsers.Povfwctx.Profiling = true
	}
	/*
		Reset CTX grok to reduce memory footprint after we compile all the patterns
	*/
	parsers.Ctx.Grok = grokky.Host{}
	parsers.Povfwctx.Grok = grokky.Host{}
	parsers.StageFiles = []Stagefile{}
	parsers.PovfwStageFiles = []Stagefile{}
	return parsers, nil
}