package classes

import (
	"fmt"
	"regexp"
	"strings"
	"time"

	"git.golem15.com/golem15/sm-sitemap-plugin/models"
	"git.golem15.com/golem15/summercms/modules/lagoon"
	"git.golem15.com/golem15/summercms/modules/pact"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

// The phrase keys of the content type refusals (UI-SPEC C26).
const (
	errSlug      = "golem15.sitemap::lang.errors.slug"
	errSlugTaken = "golem15.sitemap::lang.errors.slug_taken"
)

var typeFieldUnsafe = regexp.MustCompile(`[^a-z0-9_]`)

// TypeFieldBase is the prefix of a content type's settings fields:
// type_<key>_, where every character of the key outside [a-z0-9_] becomes
// "_".
func TypeFieldBase(key string) string {
	return "type_" + typeFieldUnsafe.ReplaceAllString(strings.ToLower(key), "_") + "_"
}

// SaveTypeSettings stores submitted content type settings: values holds
// TypeFieldBase(key)+"include" (a switch), +"slug" and +"title" (a locale
// map) per type; a type or value not sent keeps what is stored. A slug
// outside [a-z0-9-] is refused with errors.slug, one that another type (or
// the image and News sitemaps) uses with errors.slug_taken; an empty slug
// is the type's default. Refusals are by field name; nothing is written
// while there are any.
func SaveTypeSettings(db *gorm.DB, types []pact.MenuItemType, values map[string]any) (map[string][]string, error) {
	rows, err := LoadTypeSettings(db)
	if err != nil {
		return nil, err
	}
	refusals := map[string][]string{}
	next := make([]models.TypeSetting, 0, len(types))
	slugOwner := map[string]string{}
	for _, typ := range types {
		base := TypeFieldBase(typ.Key)
		cfg := EffectiveType(typ, rows)
		row, ok := rows[typ.Key]
		if !ok {
			row = models.TypeSetting{TypeKey: typ.Key, Include: true}
		}
		if raw, sent := values[base+"include"]; sent {
			row.Include = truthy(raw)
		}
		slug := cfg.Slug
		if raw, sent := values[base+"slug"]; sent {
			slug = strings.TrimSpace(stringOf(raw))
			if slug == "" {
				slug = DefaultSlug(typ.Key)
			} else if !ValidSlug(slug) {
				refusals[base+"slug"] = append(refusals[base+"slug"], errSlug)
			}
		}
		if ReservedSlugs[slug] {
			refusals[base+"slug"] = append(refusals[base+"slug"], errSlugTaken)
		} else if owner, taken := slugOwner[slug]; taken && owner != typ.Key {
			refusals[base+"slug"] = append(refusals[base+"slug"], errSlugTaken)
		}
		slugOwner[slug] = typ.Key
		if slug == DefaultSlug(typ.Key) {
			row.Slug = ""
		} else {
			row.Slug = slug
		}
		if raw, sent := values[base+"title"]; sent {
			row.Titles = lagoon.Jsonable[map[string]string]{Data: titlesOf(raw), Valid: true}
		}
		next = append(next, row)
	}
	if len(refusals) > 0 {
		return refusals, nil
	}
	now := time.Now().UTC()
	for _, row := range next {
		row.UpdatedAt = now
		if !row.Titles.Valid {
			row.Titles = lagoon.Jsonable[map[string]string]{Data: map[string]string{}, Valid: true}
		}
		if err := db.Clauses(clause.OnConflict{
			Columns:   []clause.Column{{Name: "type_key"}},
			DoUpdates: clause.AssignmentColumns([]string{"include", "slug", "titles", "updated_at"}),
		}).Create(&row).Error; err != nil {
			return nil, err
		}
	}
	return nil, nil
}

// titlesOf reads a submitted translatable value (a map of locale to text);
// blank texts are dropped.
func titlesOf(v any) map[string]string {
	out := map[string]string{}
	switch m := v.(type) {
	case map[string]string:
		for k, s := range m {
			if strings.TrimSpace(s) != "" {
				out[k] = strings.TrimSpace(s)
			}
		}
	case map[string]any:
		for k, s := range m {
			if text, ok := s.(string); ok && strings.TrimSpace(text) != "" {
				out[k] = strings.TrimSpace(text)
			}
		}
	}
	return out
}

// truthy reads a submitted switch value.
func truthy(v any) bool {
	switch b := v.(type) {
	case bool:
		return b
	case string:
		return b == "1" || strings.EqualFold(b, "true") || strings.EqualFold(b, "on")
	case float64:
		return b != 0
	case fmt.Stringer:
		return b.String() == "1"
	}
	return false
}

// stringOf reads a submitted text value.
func stringOf(v any) string {
	switch s := v.(type) {
	case string:
		return s
	case nil:
		return ""
	}
	return fmt.Sprint(v)
}