package console

import (
	"context"
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"time"
	"unicode"
	"unicode/utf8"

	"git.golem15.com/golem15/sm-journal-plugin/classes"
	"git.golem15.com/golem15/sm-journal-plugin/models"
	translate "git.golem15.com/golem15/sm-translate-plugin/classes"
	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/bonfire"
	"git.golem15.com/golem15/summercms/modules/cabana"
	"gorm.io/gorm"
)

// UnpublishedTitlePrefix is PHP Post::UNPUBLISHED_TITLE_PREFIX. Import strips
// it from titles so a draft-accessor export does not persist the lock mark.
const UnpublishedTitlePrefix = "🔒 "

// ImportGuard is an optional per-post check (toolbar publish permission).
type ImportGuard func(post *models.Post) error

// ImportStats is the PHP ImportPosts result line.
type ImportStats struct {
	Created int
	Updated int
	Skipped int
	Failed  int
}

// ImportPosts is journal:import-posts (PHP ImportPosts.php).
func ImportPosts(app *backpack.App) bonfire.Command {
	return bonfire.Command{
		Name:        "journal:import-posts",
		Description: "Import journal posts with translations from JSON files.",
		Flags: []bonfire.Flag{
			{Name: "path", Description: "Import directory (default: journal-export)"},
			{Name: "force", Description: "Update existing posts (default: skip existing)", Bare: true},
			{Name: "dry-run", Description: "Show what would be imported without making changes", Bare: true},
		},
		Run: func(ctx context.Context, in bonfire.Input, out bonfire.Output) error {
			path := flagOrDefault(in, "path", defaultExportPath)
			force := flagOn(in, "force")
			dry := flagOn(in, "dry-run")
			stats, err := ImportFromDir(ctx, mustDB(app), path, force, dry, out, nil)
			if err != nil {
				return err
			}
			if dry {
				out.Info("Dry run complete (no changes made).")
			}
			out.Info(fmt.Sprintf("Results: %d created, %d updated, %d skipped, %d failed",
				stats.Created, stats.Updated, stats.Skipped, stats.Failed))
			return nil
		},
	}
}

// ImportFromDir reads *.json files from dir and creates or updates posts.
func ImportFromDir(ctx context.Context, gdb *gorm.DB, dir string, force, dry bool, out bonfire.Output, guard ImportGuard) (ImportStats, error) {
	var stats ImportStats
	if gdb == nil {
		return stats, fmt.Errorf("journal: database is not configured")
	}
	info, err := os.Stat(dir)
	if err != nil || !info.IsDir() {
		return stats, fmt.Errorf("Import directory not found: %s", dir)
	}
	files, err := filepath.Glob(filepath.Join(dir, "*.json"))
	if err != nil {
		return stats, err
	}
	if len(files) == 0 {
		if out != nil {
			out.Warning("No JSON files found in: " + dir)
		}
		return stats, fmt.Errorf("no JSON files found in: %s", dir)
	}
	work := func(tx *gorm.DB) error {
		for _, file := range files {
			raw, err := os.ReadFile(file)
			if err != nil {
				if out != nil {
					out.Error("  Invalid JSON: " + filepath.Base(file))
				}
				stats.Failed++
				continue
			}
			var data PostFile
			if err := json.Unmarshal(raw, &data); err != nil {
				if out != nil {
					out.Error("  Invalid JSON: " + filepath.Base(file))
				}
				stats.Failed++
				continue
			}
			if strings.TrimSpace(data.Slug) == "" {
				if out != nil {
					out.Error("  Missing slug in: " + filepath.Base(file))
				}
				stats.Failed++
				continue
			}
			result, err := importPost(ctx, tx, data, force, dry, out, guard)
			if err != nil {
				return err
			}
			switch result {
			case "created":
				stats.Created++
			case "updated":
				stats.Updated++
			case "skipped":
				stats.Skipped++
			default:
				stats.Failed++
			}
		}
		return nil
	}
	if dry {
		if err := work(gdb.WithContext(ctx).Session(&gorm.Session{NewDB: true})); err != nil {
			return stats, err
		}
		return stats, nil
	}
	err = gdb.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		return work(tx)
	})
	return stats, err
}

func importPost(ctx context.Context, db *gorm.DB, data PostFile, force, dry bool, out bonfire.Output, guard ImportGuard) (string, error) {
	var existing models.Post
	err := db.Where("slug = ?", data.Slug).Take(&existing).Error
	found := err == nil
	if err != nil && err != gorm.ErrRecordNotFound {
		return "failed", err
	}
	if found && !force {
		line(out, "  [skip] %s (already exists)", data.Slug)
		return "skipped", nil
	}
	post := &models.Post{}
	label := "created"
	if found {
		post = &existing
		label = "updated"
		if dry {
			label = "would update"
		}
	} else if dry {
		label = "would create"
	}
	line(out, "  [%s] %s", label, data.Slug)
	if dry {
		draft := &models.Post{}
		if found {
			*draft = existing
		}
		fillPost(db, draft, data)
		if guard != nil {
			if err := guard(draft); err != nil {
				return "failed", err
			}
		}
		if found {
			return "updated", nil
		}
		return "created", nil
	}
	fillPost(db, post, data)
	if guard != nil {
		if err := guard(post); err != nil {
			return "failed", err
		}
	}
	html, err := classes.FormatHTML(post.Content)
	if err != nil {
		return "failed", err
	}
	post.ContentHTML = html
	if found {
		if err := db.Save(post).Error; err != nil {
			return "failed", err
		}
	} else {
		if err := db.Create(post).Error; err != nil {
			return "failed", err
		}
	}
	if err := syncCategories(ctx, db, post, data, out); err != nil {
		return "failed", err
	}
	if err := syncTranslations(ctx, db, post, data.Translations); err != nil {
		return "failed", err
	}
	if found {
		return "updated", nil
	}
	return "created", nil
}

func fillPost(db *gorm.DB, post *models.Post, data PostFile) {
	post.Title = stripUnpublishedTitlePrefix(data.Title)
	post.Slug = data.Slug
	post.Content = data.Content
	post.Excerpt = data.Excerpt
	post.Metadata = encodeJSONField(data.Metadata)
	post.Sources = encodeJSONField(data.Sources)
	post.Published = data.Published
	post.PublishedAt = parsePublishedAt(data.PublishedAt)
	if data.AuthorEmail == "" || post.UserID != nil {
		return
	}
	var author cabana.BackendUser
	if err := db.Where("email = ?", data.AuthorEmail).Take(&author).Error; err != nil {
		return
	}
	id := author.ID
	post.UserID = &id
}

func parsePublishedAt(s *string) *time.Time {
	if s == nil || strings.TrimSpace(*s) == "" {
		return nil
	}
	raw := strings.TrimSpace(*s)
	for _, layout := range []string{time.RFC3339, "2006-01-02 15:04:05", "2006-01-02T15:04:05Z", "2006-01-02"} {
		if t, err := time.Parse(layout, raw); err == nil {
			return &t
		}
	}
	return nil
}

func encodeJSONField(v any) *string {
	if v == nil {
		return nil
	}
	if s, ok := v.(string); ok {
		if strings.TrimSpace(s) == "" {
			return nil
		}
		return &s
	}
	b, err := json.Marshal(v)
	if err != nil {
		return nil
	}
	t := string(b)
	return &t
}

func syncCategories(ctx context.Context, db *gorm.DB, post *models.Post, data PostFile, out bonfire.Output) error {
	if len(data.Categories) == 0 {
		return nil
	}
	var cats []models.Category
	for _, slug := range data.Categories {
		slug = strings.TrimSpace(slug)
		if slug == "" {
			continue
		}
		var cat models.Category
		err := db.Where("slug = ?", slug).Take(&cat).Error
		if err == gorm.ErrRecordNotFound {
			name := data.CategoryNames[slug]
			if name == "" {
				name = titleFromSlug(slug)
			}
			cat = models.Category{Name: name, Slug: slug}
			if err := db.Create(&cat).Error; err != nil {
				return err
			}
			if out != nil {
				out.Info("    Created category: " + slug)
			}
		} else if err != nil {
			return err
		}
		cats = append(cats, cat)
	}
	if len(cats) == 0 {
		return nil
	}
	return db.WithContext(ctx).Model(post).Association("Categories").Replace(cats)
}

func titleFromSlug(slug string) string {
	parts := strings.Split(strings.ReplaceAll(slug, "-", " "), " ")
	for i, p := range parts {
		if p == "" {
			continue
		}
		r, size := utf8.DecodeRuneInString(p)
		parts[i] = string(unicode.ToUpper(r)) + p[size:]
	}
	return strings.Join(parts, " ")
}

func syncTranslations(ctx context.Context, db *gorm.DB, post *models.Post, translations map[string]map[string]any) error {
	if len(translations) == 0 {
		return nil
	}
	fields := []string{"title", "slug", "content", "content_html", "excerpt", "metadata"}
	for locale, attrs := range translations {
		for _, field := range fields {
			val, ok := attrs[field]
			if !ok || val == nil {
				continue
			}
			if field == "title" {
				if s, isStr := val.(string); isStr {
					val = stripUnpublishedTitlePrefix(s)
				}
			}
			if err := translate.SetTranslated(ctx, db, post, field, locale, val); err != nil {
				return err
			}
		}
	}
	return nil
}

func stripUnpublishedTitlePrefix(title string) string {
	for strings.HasPrefix(title, UnpublishedTitlePrefix) {
		title = strings.TrimPrefix(title, UnpublishedTitlePrefix)
	}
	return title
}

func IOPayloadPath(raw []byte, fallback string) (path string, dry, force bool) {
	path = fallback
	if len(raw) == 0 {
		return path, false, false
	}
	var body struct {
		Path   string `json:"path"`
		DryRun bool   `json:"dry_run"`
		Force  bool   `json:"force"`
	}
	if err := json.Unmarshal(raw, &body); err != nil {
		return path, false, false
	}
	if strings.TrimSpace(body.Path) != "" {
		path = strings.TrimSpace(body.Path)
	}
	return path, body.DryRun, body.Force
}