package repository

import (
	"Yimaru-Backend/internal/domain"
	"Yimaru-Backend/internal/ports"
	"context"
	"encoding/json"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgtype"
)

func NewEmailTemplateStore(s *Store) ports.EmailTemplateStore { return s }

func emailTemplateToDomain(
	id int64,
	slug string,
	name string,
	subject string,
	bodyText string,
	bodyHTML string,
	variables []byte,
	isSystem bool,
	status string,
	createdAt pgtype.Timestamptz,
	updatedAt pgtype.Timestamptz,
) (domain.EmailTemplate, error) {
	var vars []string
	if len(variables) > 0 {
		if err := json.Unmarshal(variables, &vars); err != nil {
			return domain.EmailTemplate{}, err
		}
	}
	if vars == nil {
		vars = []string{}
	}

	return domain.EmailTemplate{
		ID:        id,
		Slug:      slug,
		Name:      name,
		Subject:   subject,
		BodyText:  bodyText,
		BodyHTML:  bodyHTML,
		Variables: vars,
		IsSystem:  isSystem,
		Status:    status,
		CreatedAt: createdAt.Time,
		UpdatedAt: timePtr(updatedAt),
	}, nil
}

func marshalEmailTemplateVariables(vars []string) ([]byte, error) {
	if vars == nil {
		vars = []string{}
	}
	return json.Marshal(vars)
}

func (s *Store) CreateEmailTemplate(ctx context.Context, input domain.CreateEmailTemplateInput) (domain.EmailTemplate, error) {
	status := domain.EmailTemplateStatusActive
	if input.Status != nil {
		status = *input.Status
	}

	variablesJSON, err := marshalEmailTemplateVariables(input.Variables)
	if err != nil {
		return domain.EmailTemplate{}, err
	}

	row := s.conn.QueryRow(ctx, `
		INSERT INTO email_templates (slug, name, subject, body_text, body_html, variables, is_system, status)
		VALUES ($1, $2, $3, $4, $5, $6::jsonb, FALSE, $7)
		RETURNING id, slug, name, subject, body_text, body_html, variables, is_system, status, created_at, updated_at
	`, input.Slug, input.Name, input.Subject, input.BodyText, input.BodyHTML, variablesJSON, status)

	return scanEmailTemplateRow(row)
}

func (s *Store) UpdateEmailTemplate(ctx context.Context, id int64, input domain.UpdateEmailTemplateInput) (domain.EmailTemplate, error) {
	variablesSet := input.Variables != nil
	variablesJSON, err := marshalEmailTemplateVariables(input.Variables)
	if err != nil {
		return domain.EmailTemplate{}, err
	}

	row := s.conn.QueryRow(ctx, `
		UPDATE email_templates
		SET name = COALESCE($2, name),
		    subject = COALESCE($3, subject),
		    body_text = COALESCE($4, body_text),
		    body_html = COALESCE($5, body_html),
		    variables = CASE WHEN $6::boolean THEN $7::jsonb ELSE variables END,
		    status = COALESCE($8, status),
		    updated_at = NOW()
		WHERE id = $1
		RETURNING id, slug, name, subject, body_text, body_html, variables, is_system, status, created_at, updated_at
	`, id, input.Name, input.Subject, input.BodyText, input.BodyHTML, variablesSet, variablesJSON, input.Status)

	return scanEmailTemplateRow(row)
}

func (s *Store) GetEmailTemplateByID(ctx context.Context, id int64, includeInactive bool) (domain.EmailTemplate, error) {
	row := s.conn.QueryRow(ctx, `
		SELECT id, slug, name, subject, body_text, body_html, variables, is_system, status, created_at, updated_at
		FROM email_templates
		WHERE id = $1
		  AND ($2::boolean = TRUE OR status = 'ACTIVE')
	`, id, includeInactive)

	return scanEmailTemplateRow(row)
}

func (s *Store) GetEmailTemplateBySlug(ctx context.Context, slug string, includeInactive bool) (domain.EmailTemplate, error) {
	row := s.conn.QueryRow(ctx, `
		SELECT id, slug, name, subject, body_text, body_html, variables, is_system, status, created_at, updated_at
		FROM email_templates
		WHERE slug = $1
		  AND ($2::boolean = TRUE OR status = 'ACTIVE')
	`, slug, includeInactive)

	return scanEmailTemplateRow(row)
}

func (s *Store) ListEmailTemplates(ctx context.Context, status *string, query *string, limit int32, offset int32) ([]domain.EmailTemplate, int64, error) {
	rows, err := s.conn.Query(ctx, `
		SELECT id, slug, name, subject, body_text, body_html, variables, is_system, status, created_at, updated_at
		FROM email_templates
		WHERE ($1::text IS NULL OR status = $1)
		  AND (
		    $2::text IS NULL
		    OR slug ILIKE '%' || $2 || '%'
		    OR name ILIKE '%' || $2 || '%'
		    OR subject ILIKE '%' || $2 || '%'
		  )
		ORDER BY is_system DESC, name ASC, id ASC
		LIMIT $3 OFFSET $4
	`, toPgText(status), toPgText(query), limit, offset)
	if err != nil {
		return nil, 0, err
	}
	defer rows.Close()

	templates := make([]domain.EmailTemplate, 0)
	for rows.Next() {
		tmpl, err := scanEmailTemplateRows(rows)
		if err != nil {
			return nil, 0, err
		}
		templates = append(templates, tmpl)
	}
	if err := rows.Err(); err != nil {
		return nil, 0, err
	}

	var totalCount int64
	if err := s.conn.QueryRow(ctx, `
		SELECT COUNT(*)
		FROM email_templates
		WHERE ($1::text IS NULL OR status = $1)
		  AND (
		    $2::text IS NULL
		    OR slug ILIKE '%' || $2 || '%'
		    OR name ILIKE '%' || $2 || '%'
		    OR subject ILIKE '%' || $2 || '%'
		  )
	`, toPgText(status), toPgText(query)).Scan(&totalCount); err != nil {
		return nil, 0, err
	}

	return templates, totalCount, nil
}

func (s *Store) DeleteEmailTemplate(ctx context.Context, id int64) error {
	cmd, err := s.conn.Exec(ctx, `
		DELETE FROM email_templates
		WHERE id = $1 AND is_system = FALSE
	`, id)
	if err != nil {
		return err
	}
	if cmd.RowsAffected() == 0 {
		return pgx.ErrNoRows
	}
	return nil
}

type emailTemplateScanner interface {
	Scan(dest ...any) error
}

func scanEmailTemplateRow(row emailTemplateScanner) (domain.EmailTemplate, error) {
	var (
		id        int64
		slug      string
		name      string
		subject   string
		bodyText  string
		bodyHTML  string
		variables []byte
		isSystem  bool
		status    string
		createdAt pgtype.Timestamptz
		updatedAt pgtype.Timestamptz
	)
	if err := row.Scan(&id, &slug, &name, &subject, &bodyText, &bodyHTML, &variables, &isSystem, &status, &createdAt, &updatedAt); err != nil {
		return domain.EmailTemplate{}, err
	}
	return emailTemplateToDomain(id, slug, name, subject, bodyText, bodyHTML, variables, isSystem, status, createdAt, updatedAt)
}

func scanEmailTemplateRows(rows pgx.Rows) (domain.EmailTemplate, error) {
	var (
		id        int64
		slug      string
		name      string
		subject   string
		bodyText  string
		bodyHTML  string
		variables []byte
		isSystem  bool
		status    string
		createdAt pgtype.Timestamptz
		updatedAt pgtype.Timestamptz
	)
	if err := rows.Scan(&id, &slug, &name, &subject, &bodyText, &bodyHTML, &variables, &isSystem, &status, &createdAt, &updatedAt); err != nil {
		return domain.EmailTemplate{}, err
	}
	return emailTemplateToDomain(id, slug, name, subject, bodyText, bodyHTML, variables, isSystem, status, createdAt, updatedAt)
}