package grils

import (
	"fmt"
	"log"
	"net/http"
	"regexp"
	"strconv"
	"strings"
	"time"

	"fagott.pw/charakterin"
	"fagott.pw/grilist/cache"
	"fagott.pw/grilist/eventlogging"
	"fagott.pw/grilist/frontend"
	"fagott.pw/grilist/grilist"
	"fagott.pw/grilist/models"
	"fagott.pw/grilist/util"

	"github.com/julienschmidt/httprouter"
)

var (
	pgArrayReg = regexp.MustCompile(`(((?P<value>(([^",\\{}\s(NULL)])+|"([^"\\]|\\"|\\\\)*")))(,)?)`)
	pgValueIdx int
)

func findIdx() {
	for i, subexp := range pgArrayReg.SubexpNames() {
		if subexp == "value" {
			pgValueIdx = i
			break
		}
	}
}

type GrilsModule struct {
	g *grilist.Grilist
	c *cache.Cache
}

func (m *GrilsModule) Name() string {
	return "Grils"
}

func (m *GrilsModule) Init(g *grilist.Grilist) {
	findIdx()
	m.g = g
	m.g.Router.GET("/gril/:id", m.viewGril)
	m.g.Router.GET("/gril/:id/*rest", m.viewGril)

	m.c = cache.New()
}

func (m *GrilsModule) getGrils(whereClause string, params ...interface{}) ([]*models.Gril, error) {
	var grils []*models.Gril

	rows, err := m.g.DB.Query(fmt.Sprintf(`SELECT id, kanji_name, romaji_name, other_names, updated_at, age, birthday, tags FROM grilist.grils_flattened WHERE %s`, whereClause), params...)
	if err != nil {
		return nil, err
	}

	defer rows.Close()
	for rows.Next() {
		gril := &models.Gril{}
		var tags []byte
		var otherNames []byte

		var kanjiName *string
		err = rows.Scan(&gril.ID, &kanjiName, &gril.RomajiName, &otherNames, &gril.UpdatedAt, &gril.Age, &gril.Birthday, &tags)
		if err != nil {
			log.Println(gril.ID)
			log.Println("error scanning in getGrils:", err)
			continue
		}
		if kanjiName != nil {
			gril.KanjiName = *kanjiName
		}

		gril.Tags = pgArray(tags)
		gril.OtherNames = pgArray(otherNames)

		m.c.Insert(gril.ID, gril)

		grils = append(grils, gril)
	}

	return grils, nil
}

func (m *GrilsModule) GetListsOfGril(gril *models.Gril) error {
	rows, err := m.g.DB.Query(`SELECT list_id FROM grilist.lists_grils WHERE gril_id = $1`, gril.ID)
	if err != nil {
		return err
	}

	defer rows.Close()
	for rows.Next() {
		var listID int
		if err := rows.Scan(&listID); err != nil {
			log.Println(err)
			continue
		}

		gril.Lists = append(gril.Lists, listID)
	}

	return nil
}

func (m *GrilsModule) ProvideDashboardData(user *charakterin.User) []grilist.DashboardCategory {
	var categories []grilist.DashboardCategory
	t1 := time.Now()

	rows, err := m.g.DB.Query(
		`SELECT id, romaji_name, kanji_name FROM grilist.get_recently_updated_grils();`)
	if err != nil {
		log.Println(err)
		return categories
	}
	defer rows.Close()

	cat := grilist.DashboardCategory{
		Title: "Neue Grils",
	}

	for rows.Next() {
		var g models.Gril
		if err := rows.Scan(&g.ID, &g.RomajiName, &g.KanjiName); err != nil {
			log.Println(err)
			continue
		}

		cat.Cards = append(cat.Cards, frontend.Card{
			Title:       g.RomajiName,
			Description: g.KanjiName,
			Size:        "medium",
			Actions: []frontend.Action{
				frontend.Action{
					Name: "anguckieren",
					Link: "/gril/" + g.Slug(),
				},
			},
		})
	}
	categories = append(categories, cat)
	log.Printf("get_newest_grils_overall: %dms", time.Since(t1).Nanoseconds()/1000000)
	return categories
}

func (m *GrilsModule) FromID(id int) (*models.Gril, error) {
	if g, ok := m.c.Get(id); ok {
		return g.(*models.Gril), nil
	}

	gril := &models.Gril{
		ID: id,
	}
	t1 := time.Now()
	err := m.g.DB.QueryRow(`SELECT updated_at, age, birthday FROM grilist.grils WHERE id = $1`, id).Scan(&gril.UpdatedAt, &gril.Age, &gril.Birthday)
	log.Printf("get_gril_from_id_raw: %dms", time.Since(t1).Nanoseconds()/1000000)

	if err != nil {
		return nil, err
	}

	// Namen rausholen
	rows, err := m.g.DB.Query(`SELECT name, name_type FROM grilist.gril_names WHERE gril_id = $1`, id)
	if err != nil {
		return nil, err
	}
	log.Printf("get_gril_from_id_names: %dms", time.Since(t1).Nanoseconds()/1000000)
	defer rows.Close()

	for rows.Next() {
		var name *string
		var name_type int
		if err := rows.Scan(&name, &name_type); err != nil {
			return nil, err
		}

		switch name_type {
		case 0:
			gril.KanjiName = *name
			break
		case 1:
			gril.RomajiName = *name
		default:
			gril.OtherNames = append(gril.OtherNames, *name)
		}
	}

	m.c.Insert(id, gril)
	log.Printf("get_gril_from_id: %dms", time.Since(t1).Nanoseconds()/1000000)
	return gril, nil
}

func (m *GrilsModule) FromIDs(ids []int) ([]*models.Gril, error) {
	if len(ids) == 0 {
		return make([]*models.Gril, 0), nil
	}

	t1 := time.Now()
	idList := "("
	first := true
	var list []*models.Gril
	for _, v := range ids {
		if m.c.Has(v) {
			g, _ := m.c.Get(v)
			list = append(list, g.(*models.Gril))
			continue
		}
		if first {
			first = false
		} else {
			idList += ","
		}
		idList += strconv.Itoa(v)
	}
	idList += ")"
	grils, err := m.getGrils("id IN " + idList)

	for _, g := range grils {
		list = append(list, g)
	}
	log.Printf("get_gril_from_ids: %dms", time.Since(t1).Nanoseconds()/1000000)
	return list, err
}

func (m *GrilsModule) viewGril(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
	user, _ := m.g.Charakterin.GetUserFromRequest(r)
	el := m.g.EventLogger(r)

	id, err := util.ParseIDFromParams(p)
	if err != nil {
		http.Redirect(w, r, "/", 302)
		return
	}

	gril, err := m.FromID(id)
	if err != nil {
		http.Redirect(w, r, "/", 302)
		return
	}

	if err := m.GetListsOfGril(gril); err != nil {
		log.Println(err)
	}

	data := m.g.Renderer.DefaultData()
	data["user"] = user
	data["gril"] = gril

	// ähnliche grils holen
	rows, err := m.g.DB.Query(`SELECT gril_id FROM (
		SELECT DISTINCT gril_id FROM grils_appearances WHERE appearance_id IN (SELECT appearance_id FROM grils_appearances WHERE gril_id = $1)
		) as t ORDER BY RANDOM() LIMIT 4;`, id)
	if err != nil {
		log.Println("could not get similar grils:", err)
		http.Error(w, "500", http.StatusInternalServerError)
		return
	}

	defer rows.Close()
	var similar []*models.Gril
	for rows.Next() {
		var id int
		if err := rows.Scan(&id); err != nil {
			log.Println("error scanning for similar gril:", err)
			continue
		}

		g, err := m.FromID(id)
		if err != nil {
			log.Println("invalid similar gril:", err)
			continue
		}
		similar = append(similar, g)
	}
	data["SimilarGrils"] = similar

	m.g.Renderer.RenderPage("gril", w, data)
	el.ViewGril(user, eventlogging.ViewGrilData{
		GrilID: gril.ID,
	})
}

func pgArray(array []byte) []string {
	var results []string
	matches := pgArrayReg.FindAllStringSubmatch(string(array), -1)
	for _, match := range matches {
		s := match[pgValueIdx]
		s = strings.Trim(s, "\"")
		results = append(results, s)
	}
	return results
}

func New() *GrilsModule {
	return &GrilsModule{}
}