package sqlite

import (
	"context"
	"database/sql"
	"fmt"
	"time"

	"forge.cadoles.com/arcad/edge/pkg/app"
	"forge.cadoles.com/arcad/edge/pkg/module/share"
	"forge.cadoles.com/arcad/edge/pkg/storage/sqlite"
	"github.com/pkg/errors"
	"gitlab.com/wpetit/goweb/logger"
)

type Repository struct {
	getDB sqlite.GetDBFunc
}

// DeleteAttributes implements share.Repository
func (r *Repository) DeleteAttributes(ctx context.Context, origin app.ID, resourceID share.ResourceID, names ...string) error {
	err := r.withTx(ctx, func(tx *sql.Tx) error {
		query := `
			DELETE FROM resources 
			WHERE origin = $1 AND resource_id = $2
		`
		args := []any{origin, resourceID}
		criteria := ""

		for idx, name := range names {
			if idx == 0 {
				criteria += " AND ("
			}

			if idx != 0 {
				criteria += " OR "
			}

			criteria += fmt.Sprintf(" name = $%d", len(args)+1)
			args = append(args, name)

			if idx == len(names)-1 {
				criteria += " )"
			}
		}

		query += criteria

		logger.Debug(
			ctx, "executing query",
			logger.F("query", query),
			logger.F("args", args),
		)

		res, err := tx.ExecContext(ctx, query, args...)
		if err != nil {
			return errors.WithStack(err)
		}

		affected, err := res.RowsAffected()
		if err != nil {
			return errors.WithStack(err)
		}

		if affected == 0 {
			return errors.WithStack(share.ErrNotFound)
		}

		return nil
	})
	if err != nil {
		return errors.WithStack(err)
	}

	return err
}

// DeleteResource implements share.Repository
func (r *Repository) DeleteResource(ctx context.Context, origin app.ID, resourceID share.ResourceID) error {
	err := r.withTx(ctx, func(tx *sql.Tx) error {
		query := `
			DELETE FROM resources 
			WHERE origin = $1 AND resource_id = $2
		`

		args := []any{origin, resourceID}

		logger.Debug(
			ctx, "executing query",
			logger.F("query", query),
			logger.F("args", args),
		)

		res, err := tx.ExecContext(ctx, query, args...)
		if err != nil {
			return errors.WithStack(err)
		}

		affected, err := res.RowsAffected()
		if err != nil {
			return errors.WithStack(err)
		}

		if affected == 0 {
			return errors.WithStack(share.ErrNotFound)
		}

		return nil
	})
	if err != nil {
		return errors.WithStack(err)
	}

	return err
}

// FindResources implements share.Repository
func (r *Repository) FindResources(ctx context.Context, funcs ...share.FindResourcesOptionFunc) ([]share.Resource, error) {
	opts := share.FillFindResourcesOptions(funcs...)

	var resources []share.Resource

	err := r.withTx(ctx, func(tx *sql.Tx) error {
		query := `
			SELECT 
				main.origin, main.resource_id, 
				main.name, main.type, main.value, 
				main.created_at, main.updated_at 
			FROM resources AS main 
			JOIN resources AS sub ON 
				main.resource_id = sub.resource_id 
				AND main.origin = sub.origin
		`

		criteria := " WHERE 1 = 1"
		preparedArgIndex := 1
		args := make([]any, 0)

		if opts.Name != nil {
			criteria += fmt.Sprintf(" AND sub.name = $%d", preparedArgIndex)
			args = append(args, *opts.Name)
			preparedArgIndex++
		}

		if opts.ValueType != nil {
			criteria += fmt.Sprintf(" AND sub.type = $%d", preparedArgIndex)
			args = append(args, *opts.ValueType)
			preparedArgIndex++
		}

		query += criteria

		logger.Debug(
			ctx, "executing query",
			logger.F("query", query),
			logger.F("args", args),
		)

		rows, err := tx.QueryContext(ctx, query, args...)
		if err != nil {
			return errors.WithStack(err)
		}

		defer func() {
			if err := rows.Close(); err != nil {
				logger.Error(ctx, "could not close rows", logger.E(errors.WithStack(err)))
			}
		}()

		indexedResources := make(map[string]*share.BaseResource)

		for rows.Next() {
			var (
				origin     string
				resourceID string
				name       string
				valueType  string
				value      any
				updatedAt  time.Time
				createdAt  time.Time
			)

			if err := rows.Scan(&origin, &resourceID, &name, &valueType, &value, &createdAt, &updatedAt); err != nil {
				return errors.WithStack(err)
			}

			resourceKey := origin + resourceID
			resource, exists := indexedResources[resourceKey]
			if !exists {
				resource = share.NewBaseResource(app.ID(origin), share.ResourceID(resourceID))
				indexedResources[resourceKey] = resource
			}

			attr := share.NewBaseAttribute(
				name,
				share.ValueType(valueType),
				value,
			)

			attr.SetCreatedAt(createdAt)
			attr.SetUpdatedAt(updatedAt)

			resource.SetAttribute(attr)
		}

		if err := rows.Err(); err != nil {
			return errors.WithStack(err)
		}

		resources = make([]share.Resource, 0, len(indexedResources))
		for _, res := range indexedResources {
			resources = append(resources, res)
		}

		return nil
	})
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return resources, nil
}

// GetResource implements share.Repository
func (r *Repository) GetResource(ctx context.Context, origin app.ID, resourceID share.ResourceID) (share.Resource, error) {
	var (
		resource *share.BaseResource
		err      error
	)

	err = r.withTx(ctx, func(tx *sql.Tx) error {
		resource, err = r.getResourceWithinTx(ctx, tx, origin, resourceID)
		if err != nil {
			return errors.WithStack(err)
		}

		return nil
	})
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return resource, nil
}

// UpdateAttributes implements share.Repository
func (r *Repository) UpdateAttributes(ctx context.Context, origin app.ID, resourceID share.ResourceID, attributes ...share.Attribute) (share.Resource, error) {
	if len(attributes) == 0 {
		return nil, errors.WithStack(share.ErrAttributeRequired)
	}

	var resource *share.BaseResource
	err := r.withTx(ctx, func(tx *sql.Tx) error {
		query := `
		INSERT INTO resources (origin, resource_id, name, type, value, created_at, updated_at) 
		VALUES($1, $2, $3, $4, $5, $6, $6)
		ON CONFLICT (origin, resource_id, name) DO UPDATE SET
			type = $4, value = $5, updated_at = $6
		`

		stmt, err := tx.PrepareContext(ctx, query)
		if err != nil {
			return errors.WithStack(err)
		}

		defer func() {
			if err := stmt.Close(); err != nil {
				logger.Error(ctx, "could not close statement", logger.E(errors.WithStack(err)))
			}
		}()

		now := time.Now().UTC()

		for _, attr := range attributes {
			args := []any{
				string(origin), string(resourceID),
				attr.Name(), string(attr.Type()), attr.Value(),
				now, now,
			}

			logger.Debug(
				ctx, "executing query",
				logger.F("query", query),
				logger.F("args", args),
			)

			if _, err := stmt.ExecContext(ctx, args...); err != nil {
				return errors.WithStack(err)
			}
		}

		resource, err = r.getResourceWithinTx(ctx, tx, origin, resourceID)
		if err != nil {
			return errors.WithStack(err)
		}

		return nil
	})
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return resource, nil
}

func (r *Repository) getResourceWithinTx(ctx context.Context, tx *sql.Tx, origin app.ID, resourceID share.ResourceID) (*share.BaseResource, error) {
	query := `
			SELECT name, type, value, created_at, updated_at 
			FROM resources
			WHERE origin = $1 AND resource_id = $2
		`

	rows, err := tx.QueryContext(ctx, query, origin, resourceID)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	defer func() {
		if err := rows.Close(); err != nil {
			logger.Error(ctx, "could not close rows", logger.E(errors.WithStack(err)))
		}
	}()

	attributes := make([]share.Attribute, 0)

	for rows.Next() {
		var (
			name      string
			valueType string
			value     any
			updatedAt time.Time
			createdAt time.Time
		)

		if err := rows.Scan(&name, &valueType, &value, &createdAt, &updatedAt); err != nil {
			return nil, errors.WithStack(err)
		}

		attr := share.NewBaseAttribute(
			name,
			share.ValueType(valueType),
			value,
		)

		attr.SetCreatedAt(createdAt)
		attr.SetUpdatedAt(updatedAt)

		attributes = append(attributes, attr)
	}

	if err := rows.Err(); err != nil {
		return nil, errors.WithStack(err)
	}

	if len(attributes) == 0 {
		return nil, errors.WithStack(share.ErrNotFound)
	}

	resource := share.NewBaseResource(origin, resourceID, attributes...)

	return resource, nil
}

func (r *Repository) withTx(ctx context.Context, fn func(tx *sql.Tx) error) error {
	var db *sql.DB

	db, err := r.getDB(ctx)
	if err != nil {
		return errors.WithStack(err)
	}

	if err := sqlite.WithTx(ctx, db, fn); err != nil {
		return errors.WithStack(err)
	}

	return nil
}

func ensureTables(ctx context.Context, db *sql.DB) error {
	err := sqlite.WithTx(ctx, db, func(tx *sql.Tx) error {
		query := `
			CREATE TABLE IF NOT EXISTS resources (
				resource_id TEXT NOT NULL,
				origin TEXT NOT NULL,
				name TEXT NOT NULL,
				type TEXT NOT NULL,
				value TEXT,
				created_at TIMESTAMP NOT NULL,
				updated_at TIMESTAMP NOT NULL,
				UNIQUE(origin, resource_id, name) ON CONFLICT REPLACE
			);
		`
		if _, err := tx.ExecContext(ctx, query); err != nil {
			return errors.WithStack(err)
		}

		query = `
			CREATE INDEX IF NOT EXISTS resource_idx ON resources (origin, resource_id, name);
		`
		if _, err := tx.ExecContext(ctx, query); err != nil {
			return errors.WithStack(err)
		}

		return nil
	})
	if err != nil {
		return errors.WithStack(err)
	}

	return nil
}

func NewRepository(path string) *Repository {
	getDB := sqlite.NewGetDBFunc(path, ensureTables)

	return &Repository{
		getDB: getDB,
	}
}

func NewRepositoryWithDB(db *sql.DB) *Repository {
	getDB := sqlite.NewGetDBFuncFromDB(db, ensureTables)

	return &Repository{
		getDB: getDB,
	}
}

var _ share.Repository = &Repository{}