package models

import (
	"errors"
	"fmt"
	"regexp"
	"strings"
	"time"

	"github.com/coder/websocket/wsjson"
	"github.com/google/uuid"
	serverModels "github.com/tecamino/tecamino-dbm/server/models"
	"github.com/tecamino/tecamino-dbm/utils"
)

const (
	OnCreate = "onCreate"
	OnChange = "onChange"
	OnDelete = "onDelete"
)

type Datapoint struct {
	Datapoints     map[string]*Datapoint `json:"-"`
	Uuid           uuid.UUID             `json:"uuid"`
	Path           string                `json:"path"`
	Value          any                   `json:"value,omitempty"`
	CreateDateTime int64                 `json:"createDateTime,omitempty"`
	UpdateDateTime int64                 `json:"updateDateTime,omitempty"`
	Type           Type                  `json:"type"`
	ReadWrite      Rights                `json:"readWrite"`
	Drivers        Drivers               `json:"drivers,omitempty"`
	Subscriptions  Subscriptions         `json:"-"`
}

func (d *Datapoint) Set(path string, set Set) (bool, error) {
	var changed bool
	if path != "" {
		changed = true
		d.Path = path
	}

	if set.Type != nil {
		changed = true
		d.Type = *set.Type
	}

	if d.Type != "" {
		if d.Value == nil && set.Value == nil {
			changed = true
			d.Value = d.Type.DefaultValue()
		} else if d.Value != d.Type.ConvertValue(set.Value) {
			changed = true
			d.Value = d.Type.ConvertValue(set.Value)
		}

	}
	if set.Rights != nil {
		changed = true
		d.ReadWrite = set.Rights.GetRights()
	}

	if changed {
		d.UpdateDateTime = time.Now().UnixMilli()
	}

	if set.Driver == nil {
		return changed, nil
	}
	if set.Driver.Type == "" {
		return changed, errors.New("driver type missing")
	}
	if set.Driver.Bus == "" {
		return changed, errors.New("driver bus name missing")
	}

	if d.Drivers == nil {
		d.Drivers = NewDrivers()
	}
	d.Drivers.AddDriver(set.Driver.Type, set.Driver.Bus, set.Driver.Address)
	d.UpdateDateTime = time.Now().UnixMilli()

	return changed, nil
}

func (d *Datapoint) GetValueUint64() uint64 {
	return utils.Uint64From(d.Value)
}

func (d *Datapoint) CreateDatapoints(conns *serverModels.Connections, sets ...Set) (created []Set, err error) {
	if len(sets) == 0 {
		return
	}
	for _, dp := range sets {
		parts := strings.Split(dp.Path, ":")

		current := d
		for i, part := range parts {
			if current.Datapoints == nil {
				current.Datapoints = make(map[string]*Datapoint)
			}

			if i == len(parts)-1 {
				// Leaf node: create or update datapoint
				if existing, ok := current.Datapoints[part]; ok {
					publish, err := existing.Set("", dp)
					if err != nil {
						return nil, err
					}
					created = append(created, Set{
						Path:    existing.Path,
						Type:    &existing.Type,
						Value:   existing.Value,
						Rights:  &existing.ReadWrite,
						Drivers: &existing.Drivers,
						Updated: true,
					})

					if publish {
						existing.Publish(conns, OnChange)
					}
				} else {
					// Create new
					current.Datapoints[part] = &Datapoint{
						Uuid:           uuid.New(),
						CreateDateTime: time.Now().UnixMilli(),
						Subscriptions:  InitSubscribtion(),
					}
					publish, err := current.Datapoints[part].Set(strings.Join(parts, ":"), dp)
					if err != nil {
						return nil, err
					}
					created = append(created, Set{
						Path:   current.Path,
						Type:   &current.Type,
						Value:  current.Value,
						Rights: &current.ReadWrite,
						Driver: dp.Driver,
					})
					if publish {
						current.Publish(conns, OnChange)
					}
				}
				return
			}

			// Traverse or create intermediate datapoints
			if next, ok := current.Datapoints[part]; ok {
				current = next
			} else {
				newDp := &Datapoint{
					Uuid:           uuid.New(),
					Path:           strings.Join(parts[:i+1], ":"),
					Type:           NONE,
					CreateDateTime: time.Now().UnixMilli(),
					UpdateDateTime: time.Now().UnixMilli(),
					Subscriptions:  InitSubscribtion(),
				}

				if dp.Rights != nil {
					newDp.ReadWrite = dp.Rights.GetRights()
				}

				current.Datapoints[part] = newDp
				current = newDp
			}
		}
	}
	return
}

func (d *Datapoint) ImportDatapoint(conns *serverModels.Connections, dp Datapoint, path string) error {
	parts := strings.Split(dp.Path, ":")

	current := d
	for i, part := range parts {
		if current.Datapoints == nil {
			current.Datapoints = make(map[string]*Datapoint)
		}

		if i == len(parts)-1 {
			// Leaf node: import the datapoint
			if existing, ok := current.Datapoints[part]; ok {
				existing.Type = dp.Type
				existing.Value = current.Type.ConvertValue(dp.Value)
				existing.ReadWrite = dp.ReadWrite.GetRights()
				existing.UpdateDateTime = time.Now().UnixMilli()
				dp.Publish(conns, OnChange)
			} else {
				dp.Path = strings.Join(parts, ":")
				dp.ReadWrite = dp.ReadWrite.GetRights()
				dp.UpdateDateTime = time.Now().UnixMilli()
				dp.Subscriptions = InitSubscribtion()
				current.Datapoints[part] = &dp
				dp.Publish(conns, OnChange)
			}
			return nil
		}

		// Traverse or create intermediate nodes
		if next, ok := current.Datapoints[part]; ok {
			current = next
		} else {
			newDp := &Datapoint{
				Path:           strings.Join(parts[:i+1], ":"),
				Type:           NONE,
				ReadWrite:      dp.ReadWrite.GetRights(),
				UpdateDateTime: time.Now().UnixMilli(),
			}
			newDp.ReadWrite = newDp.ReadWrite.GetRights()
			current.Datapoints[part] = newDp
			current = newDp
		}
	}
	return nil
}

func (d *Datapoint) UpdateDatapointValue(conns *serverModels.Connections, value any, path string) error {

	paths := strings.Split(path, ":")

	current := d
	for i, part := range paths {
		dp, ok := current.Datapoints[part]
		if !ok {
			return fmt.Errorf("datapoint path not found: %s (at %s)", path, part)
		}
		if i == len(paths)-1 {
			dp.Value = dp.Type.ConvertValue(value)
			dp.UpdateDateTime = time.Now().UnixMilli()
			dp.Publish(conns, OnChange)
			return nil
		}
		current = dp
	}
	return nil
}

func (d *Datapoint) RemoveDatapoint(conns *serverModels.Connections, set Set) (Set, error) {
	parts := strings.Split(set.Path, ":")

	if len(parts) < 1 {
		return Set{}, fmt.Errorf("invalid path: '%s'", set.Path)
	}

	current := d
	for i := range len(parts) - 1 {
		next, ok := current.Datapoints[parts[i]]
		if !ok {
			return Set{}, fmt.Errorf("path not found: '%s'", strings.Join(parts[:i+1], ":"))
		}
		current = next
	}

	toDelete := parts[len(parts)-1]
	if dp, ok := current.Datapoints[toDelete]; ok {
		dp.Publish(conns, OnDelete)
		delete(current.Datapoints, toDelete)
		return Set{
			Path: set.Path,
		}, nil
	}
	return Set{}, fmt.Errorf("datapoint '%s' not found", set.Path)
}

func (d *Datapoint) GetAllDatapoints(depth int) (dps []*Datapoint) {

	var dfs func(dp *Datapoint, currentDepth int)
	dfs = func(dp *Datapoint, currentDepth int) {
		if depth == 1 {
			return
		} else if depth == 0 {
			// Return all descendants
			for _, child := range dp.Datapoints {
				dps = append(dps, child)
				dfs(child, currentDepth+1)
			}
			return
		}

		if currentDepth == depth-1 {
			return
		}

		for _, child := range dp.Datapoints {
			dps = append(dps, child)
			dfs(child, currentDepth+1)
		}
	}
	dps = append(dps, d)
	dfs(d, 0)
	return
}

func (d *Datapoint) QueryDatapoints(depth int, path string) (dps []*Datapoint) {
	parts := strings.Split(path, ":")

	var dfs func(current *Datapoint, index int)
	dfs = func(current *Datapoint, index int) {

		if index == len(parts) {
			dps = append(dps, current.GetAllDatapoints(depth)...)
			return
		}

		pattern := "^" + parts[index] + "$"
		re, err := regexp.Compile(pattern)
		if err != nil {
			return
		}

		for name, dp := range current.Datapoints {
			if re.MatchString(name) {
				dfs(dp, index+1)
			}
		}
	}

	dfs(d, 0)
	return
}

func (d *Datapoint) AddSubscribtion(id string, sub *Subscribe) {
	if d.Subscriptions == nil {
		return
	}

	if s, ok := d.Subscriptions[id]; ok {
		s.OnCreate = sub.GetOnCreate()
		s.OnChange = sub.GetOnChange()
		s.OnDelete = sub.GetOnDelete()
	} else {
		d.Subscriptions[id] = &Subscription{
			OnCreate: sub.GetOnCreate(),
			OnChange: sub.GetOnChange(),
			OnDelete: sub.GetOnDelete(),
		}
	}
}

func (d *Datapoint) RemoveSubscribtion(id string) {
	if _, ok := d.Subscriptions[id]; !ok {
		return
	}
	delete(d.Subscriptions, id)
}

func (d *Datapoint) Publish(conns *serverModels.Connections, eventType string) error {
	if conns.Clients == nil {
		return nil
	}
	conns.RLock()
	defer conns.RUnlock()

	for id := range d.Subscriptions {
		if client, ok := conns.Clients[id]; !ok {
			delete(d.Subscriptions, id)
		} else {
			err := wsjson.Write(client.Ctx, client.Conn, Publish{
				Event: eventType,
				Path:  d.Path,
				Value: d.Value,
			})
			if err != nil {
				return err
			}
		}
	}
	return nil
}