package classes

import (
	"context"
	"strings"

	"git.golem15.com/golem15/sm-journal-plugin/models"
	"git.golem15.com/golem15/summercms/modules/compass"
	"gorm.io/gorm"
)

// H1ToH2Key is the config key of the H1 setting, used only when the Journal
// settings row does not exist (EffectiveH1ToH2). Its shipped default is true.
const H1ToH2Key = "golem15.journal.content_h1_to_h2"

// DefaultGenericAnchors are the link texts the editor warns about when the
// settings row has no list of its own: the English and the Polish seed list,
// each entry once.
var DefaultGenericAnchors = []string{
	"click here", "here", "more", "read more", "learn more", "this link", "link",
	"kliknij tutaj", "tutaj", "tu", "więcej", "czytaj więcej", "czytaj dalej", "ten link",
}

// headingSettings is the part of the settings row the heading rules read.
type headingSettings struct {
	ContentH1ToH2  bool
	GenericAnchors *string
}

// readHeadingSettings reads the settings row (ID 1); found is false when
// there is no row or no database.
func readHeadingSettings(ctx context.Context, db *gorm.DB) (headingSettings, bool) {
	if db == nil {
		return headingSettings{}, false
	}
	if ctx != nil {
		db = db.WithContext(ctx)
	}
	var rows []headingSettings
	if err := db.Model(&models.Settings{}).Select("content_h1_to_h2", "generic_anchors").
		Where("id = ?", 1).Limit(1).Find(&rows).Error; err != nil || len(rows) == 0 {
		return headingSettings{}, false
	}
	return rows[0], true
}

// EffectiveH1ToH2 is the one reader of the H1 setting (P33-04): the settings
// row's content_h1_to_h2 decides; without a row (or a database) the config
// key golem15.journal.content_h1_to_h2 does, and true when that is unset
// too. While it is true every H1 saved in Journal rich text becomes an H2.
func EffectiveH1ToH2(ctx context.Context, db *gorm.DB, cfg *compass.Config) bool {
	if row, ok := readHeadingSettings(ctx, db); ok {
		return row.ContentH1ToH2
	}
	if cfg != nil && cfg.Has(H1ToH2Key) {
		return cfg.Bool(H1ToH2Key)
	}
	return true
}

// GenericAnchors is the list of generic link texts: the settings row's
// generic_anchors, one entry per line, trimmed and lowercased with blank
// lines dropped, or DefaultGenericAnchors when the row has no list (no
// row, NULL or only blank lines).
func GenericAnchors(ctx context.Context, db *gorm.DB) []string {
	row, ok := readHeadingSettings(ctx, db)
	if !ok || row.GenericAnchors == nil {
		return append([]string(nil), DefaultGenericAnchors...)
	}
	var out []string
	seen := map[string]bool{}
	for _, line := range strings.Split(*row.GenericAnchors, "\n") {
		entry := strings.ToLower(strings.TrimSpace(line))
		if entry == "" || seen[entry] {
			continue
		}
		seen[entry] = true
		out = append(out, entry)
	}
	if len(out) == 0 {
		return append([]string(nil), DefaultGenericAnchors...)
	}
	return out
}