package db

import (
	"context"
	"database/sql"
	"encoding/json"

	"github.com/gooseek/backend/internal/pages"
)

type PageRepository struct {
	db *PostgresDB
}

func NewPageRepository(db *PostgresDB) *PageRepository {
	return &PageRepository{db: db}
}

func (r *PageRepository) RunMigrations(ctx context.Context) error {
	migrations := []string{
		`CREATE TABLE IF NOT EXISTS pages (
			id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
			user_id UUID NOT NULL,
			thread_id UUID REFERENCES threads(id) ON DELETE SET NULL,
			title VARCHAR(500) NOT NULL,
			subtitle TEXT,
			sections JSONB NOT NULL DEFAULT '[]',
			sources JSONB NOT NULL DEFAULT '[]',
			thumbnail TEXT,
			is_public BOOLEAN DEFAULT FALSE,
			share_id VARCHAR(100) UNIQUE,
			view_count INT DEFAULT 0,
			created_at TIMESTAMPTZ DEFAULT NOW(),
			updated_at TIMESTAMPTZ DEFAULT NOW()
		)`,
		`CREATE INDEX IF NOT EXISTS idx_pages_user ON pages(user_id)`,
		`CREATE INDEX IF NOT EXISTS idx_pages_share ON pages(share_id)`,
	}

	for _, m := range migrations {
		if _, err := r.db.db.ExecContext(ctx, m); err != nil {
			return err
		}
	}
	return nil
}

func (r *PageRepository) Create(ctx context.Context, p *pages.Page) error {
	sectionsJSON, _ := json.Marshal(p.Sections)
	sourcesJSON, _ := json.Marshal(p.Sources)

	query := `
		INSERT INTO pages (user_id, thread_id, title, subtitle, sections, sources, thumbnail, is_public)
		VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
		RETURNING id, created_at, updated_at
	`

	var threadID *string
	if p.ThreadID != "" {
		threadID = &p.ThreadID
	}

	return r.db.db.QueryRowContext(ctx, query,
		p.UserID, threadID, p.Title, p.Subtitle, sectionsJSON, sourcesJSON, p.Thumbnail, p.IsPublic,
	).Scan(&p.ID, &p.CreatedAt, &p.UpdatedAt)
}

func (r *PageRepository) GetByID(ctx context.Context, id string) (*pages.Page, error) {
	query := `
		SELECT id, user_id, thread_id, title, subtitle, sections, sources, thumbnail, is_public, share_id, view_count, created_at, updated_at
		FROM pages 
		WHERE id = $1
	`

	var p pages.Page
	var sectionsJSON, sourcesJSON []byte
	var threadID, shareID sql.NullString

	err := r.db.db.QueryRowContext(ctx, query, id).Scan(
		&p.ID, &p.UserID, &threadID, &p.Title, &p.Subtitle,
		&sectionsJSON, &sourcesJSON, &p.Thumbnail,
		&p.IsPublic, &shareID, &p.ViewCount, &p.CreatedAt, &p.UpdatedAt,
	)
	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}

	json.Unmarshal(sectionsJSON, &p.Sections)
	json.Unmarshal(sourcesJSON, &p.Sources)

	if threadID.Valid {
		p.ThreadID = threadID.String
	}
	if shareID.Valid {
		p.ShareID = shareID.String
	}

	return &p, nil
}

func (r *PageRepository) GetByShareID(ctx context.Context, shareID string) (*pages.Page, error) {
	query := `
		SELECT id, user_id, thread_id, title, subtitle, sections, sources, thumbnail, is_public, share_id, view_count, created_at, updated_at
		FROM pages 
		WHERE share_id = $1 AND is_public = true
	`

	var p pages.Page
	var sectionsJSON, sourcesJSON []byte
	var threadID, shareIDVal sql.NullString

	err := r.db.db.QueryRowContext(ctx, query, shareID).Scan(
		&p.ID, &p.UserID, &threadID, &p.Title, &p.Subtitle,
		&sectionsJSON, &sourcesJSON, &p.Thumbnail,
		&p.IsPublic, &shareIDVal, &p.ViewCount, &p.CreatedAt, &p.UpdatedAt,
	)
	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}

	json.Unmarshal(sectionsJSON, &p.Sections)
	json.Unmarshal(sourcesJSON, &p.Sources)

	if threadID.Valid {
		p.ThreadID = threadID.String
	}
	if shareIDVal.Valid {
		p.ShareID = shareIDVal.String
	}

	return &p, nil
}

func (r *PageRepository) GetByUserID(ctx context.Context, userID string, limit, offset int) ([]*pages.Page, error) {
	query := `
		SELECT id, user_id, thread_id, title, subtitle, sections, sources, thumbnail, is_public, share_id, view_count, created_at, updated_at
		FROM pages 
		WHERE user_id = $1
		ORDER BY updated_at DESC
		LIMIT $2 OFFSET $3
	`

	rows, err := r.db.db.QueryContext(ctx, query, userID, limit, offset)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var pagesList []*pages.Page
	for rows.Next() {
		var p pages.Page
		var sectionsJSON, sourcesJSON []byte
		var threadID, shareID sql.NullString

		if err := rows.Scan(
			&p.ID, &p.UserID, &threadID, &p.Title, &p.Subtitle,
			&sectionsJSON, &sourcesJSON, &p.Thumbnail,
			&p.IsPublic, &shareID, &p.ViewCount, &p.CreatedAt, &p.UpdatedAt,
		); err != nil {
			return nil, err
		}

		json.Unmarshal(sectionsJSON, &p.Sections)
		json.Unmarshal(sourcesJSON, &p.Sources)

		if threadID.Valid {
			p.ThreadID = threadID.String
		}
		if shareID.Valid {
			p.ShareID = shareID.String
		}

		pagesList = append(pagesList, &p)
	}

	return pagesList, nil
}

func (r *PageRepository) Update(ctx context.Context, p *pages.Page) error {
	sectionsJSON, _ := json.Marshal(p.Sections)
	sourcesJSON, _ := json.Marshal(p.Sources)

	query := `
		UPDATE pages 
		SET title = $2, subtitle = $3, sections = $4, sources = $5, thumbnail = $6, is_public = $7, updated_at = NOW()
		WHERE id = $1
	`
	_, err := r.db.db.ExecContext(ctx, query,
		p.ID, p.Title, p.Subtitle, sectionsJSON, sourcesJSON, p.Thumbnail, p.IsPublic,
	)
	return err
}

func (r *PageRepository) SetShareID(ctx context.Context, pageID, shareID string) error {
	_, err := r.db.db.ExecContext(ctx,
		"UPDATE pages SET share_id = $2, is_public = true WHERE id = $1",
		pageID, shareID,
	)
	return err
}

func (r *PageRepository) IncrementViewCount(ctx context.Context, id string) error {
	_, err := r.db.db.ExecContext(ctx,
		"UPDATE pages SET view_count = view_count + 1 WHERE id = $1",
		id,
	)
	return err
}

func (r *PageRepository) Delete(ctx context.Context, id string) error {
	_, err := r.db.db.ExecContext(ctx, "DELETE FROM pages WHERE id = $1", id)
	return err
}