package mysqldb

import (
	"context"
	"database/sql"
	"encoding/json"
	"fmt"
	lucifer3 "git.aiterp.net/lucifer3/server"
	"git.aiterp.net/lucifer3/server/commands"
	"git.aiterp.net/lucifer3/server/effects"
	"git.aiterp.net/lucifer3/server/events"
	"git.aiterp.net/lucifer3/server/internal/gentools"
	"git.aiterp.net/lucifer3/server/services/mysqldb/mysqlgen"
	"git.aiterp.net/lucifer3/server/services/script"
	"strings"
	"time"

	_ "github.com/go-sql-driver/mysql"
)

type database struct {
	db              *sql.DB
	scriptVariables map[string]string
}

func (d *database) Active() bool {
	return true
}

func (d *database) HandleEvent(bus *lucifer3.EventBus, event lucifer3.Event) {
	q := mysqlgen.New(d.db)
	timeout, cancel := context.WithTimeout(context.Background(), time.Second*5)
	defer cancel()

	switch event := event.(type) {
	case events.Started:
		timeout, cancel := context.WithTimeout(context.Background(), time.Second*90)
		defer cancel()

		// Fetch all aliases first
		aliases, err := q.ListDeviceAliases(timeout)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_list_aliases",
				Message: "Database could not list aliases: " + err.Error(),
			})
		}

		auths, err := q.ListDeviceAuth(timeout)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_list_device_infos",
				Message: "Hardware State serialization failed: " + err.Error(),
			})
		}
		for _, auth := range auths {
			bus.RunCommand(commands.ConnectDevice{
				ID:     auth.ID,
				APIKey: auth.ApiKey,
			})
		}

		infos, err := q.ListDeviceInfos(timeout)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_list_device_infos",
				Message: "Hardware State serialization failed: " + err.Error(),
			})
		}
		for _, info := range infos {
			switch info.Kind {
			case "hardware_state":
				staleEvent := events.HardwareState{}
				err := json.Unmarshal(info.Data, &staleEvent)
				if err == nil {
					bus.RunEvent(staleEvent)
				}
			case "hardware_metadata":
				staleEvent := events.HardwareMetadata{}
				err := json.Unmarshal(info.Data, &staleEvent)
				if err == nil {
					bus.RunEvent(staleEvent)
				}
			}
		}

		// Run the aliases now
		for _, alias := range aliases {
			bus.RunCommand(commands.AddAlias{
				Match: alias.ID,
				Alias: alias.Alias,
			})
		}

		assignments, err := q.ListDeviceAssignments(timeout)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_list_assignments",
				Message: "Database could not list assignments: " + err.Error(),
			})
		}
		for _, ass := range assignments {
			effect := effects.Serializable{}
			err := json.Unmarshal(ass.Effect, &effect)
			if err != nil {
				bus.RunEvent(events.Log{
					Level:   "error",
					Code:    "database_could_not_deserialize_effect",
					Message: err.Error(),
				})
				continue
			}

			bus.RunCommand(commands.Assign{
				ID:     gentools.ShallowCopy(&ass.ID),
				Match:  ass.Match,
				Effect: effect.Effect,
			})
		}

		scripts, err := q.ListScripts(timeout)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_list_scripts",
				Message: "Database could not list scripts: " + err.Error(),
			})
		}
		for _, scr := range scripts {
			var lines []script.Line
			err := json.Unmarshal(scr.Data, &lines)
			if err != nil {
				bus.RunEvent(events.Log{
					Level:   "error",
					Code:    "database_could_not_read_script",
					Message: "Database could not read script: " + err.Error(),
				})
			}

			bus.RunCommand(script.Update{
				Name:  scr.Name,
				Lines: lines,
			})
		}

		scriptVariables, err := q.ListScriptVariables(timeout)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_list_script_variables",
				Message: "Database could not list script variables: " + err.Error(),
			})
		}
		for _, variable := range scriptVariables {
			d.scriptVariables[variable.Scope+"::"+variable.Name] = variable.Value

			cmd := script.SetVariable{
				Key:   variable.Name,
				Value: variable.Value,
			}

			scopeKind, scopeValue, _ := strings.Cut(variable.Scope, ":")
			switch scopeKind {
			case "devices":
				cmd.Devices = strings.Split(scopeValue, ";")
			case "match":
				cmd.Match = gentools.Ptr(scopeValue)
			}

			bus.RunCommand(cmd)
		}

		scriptTriggers, err := q.ListScriptTriggers(timeout)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_list_script_triggers",
				Message: "Database could not list script triggers: " + err.Error(),
			})
		}
		for _, trig := range scriptTriggers {
			bus.RunCommand(script.UpdateTrigger{
				ID:           trig.ID,
				Name:         trig.Name,
				Event:        script.TriggerEvent(trig.Event),
				DeviceMatch:  trig.DeviceMatch,
				Parameter:    trig.Parameter,
				ScriptTarget: trig.ScriptTarget,
				ScriptName:   trig.ScriptName,
				ScriptPre:    fromJSON[[]script.Line](trig.ScriptPre),
				ScriptPost:   fromJSON[[]script.Line](trig.ScriptPost),
			})
		}
	case events.DeviceAccepted:
		if event.Extras == nil {
			event.Extras = map[string]string{}
		}

		extras, err := json.Marshal(event.Extras)
		if err != nil {
			extras = []byte("{}")
		}

		err = q.ReplaceDeviceAuth(timeout, mysqlgen.ReplaceDeviceAuthParams{
			ID:     event.ID,
			ApiKey: event.APIKey,
			Extras: extras,
		})
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_save_device_auth",
				Message: "Device auth save failed: " + err.Error(),
			})
		}

	case events.HardwareState:
		if event.Stale {
			return
		}

		event.Stale = true
		serialized, err := json.Marshal(event)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_serialize_hardware_state",
				Message: "Hardware State serialization failed: " + err.Error(),
			})
			return
		}

		err = q.ReplaceDeviceInfo(timeout, mysqlgen.ReplaceDeviceInfoParams{
			ID:   event.ID,
			Kind: "hardware_state",
			Data: serialized,
		})
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_save_hardware_state",
				Message: err.Error(),
			})

			return
		}

	case events.HardwareMetadata:
		if event.Stale {
			return
		}

		event.Stale = true
		serialized, err := json.Marshal(event)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_serialize_hardware_state",
				Message: "Hardware State serialization failed: " + err.Error(),
			})
			return
		}

		err = q.ReplaceDeviceInfo(timeout, mysqlgen.ReplaceDeviceInfoParams{
			ID:   event.ID,
			Kind: "hardware_metadata",
			Data: serialized,
		})
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_save_hardware_state",
				Message: err.Error(),
			})

			return
		}

	case events.AssignmentCreated:
		serialized, err := json.Marshal(&effects.Serializable{Effect: event.Effect})
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_serialize_effect",
				Message: err.Error(),
			})
			return
		}

		err = q.ReplaceDeviceAssignment(timeout, mysqlgen.ReplaceDeviceAssignmentParams{
			ID:          event.ID,
			CreatedDate: time.Now().UTC(),
			Match:       event.Match,
			Effect:      serialized,
		})
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_save_assignment",
				Message: err.Error(),
			})
			return
		}

	case events.AssignmentRemoved:
		err := q.DeleteDeviceAssignment(timeout, event.ID)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_remove_assignment",
				Message: err.Error(),
			})
			return
		}

	case events.AliasAdded:
		err := q.InsertDeviceAlias(timeout, mysqlgen.InsertDeviceAliasParams{
			ID:    event.ID,
			Alias: event.Alias,
		})
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_remove_assignment",
				Message: err.Error(),
			})
			return
		}

	case events.AliasRemoved:
		err := q.DeleteDeviceAlias(timeout, mysqlgen.DeleteDeviceAliasParams{
			ID:    event.ID,
			Alias: event.Alias,
		})
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_remove_assignment",
				Message: err.Error(),
			})
			return
		}

	case events.DeviceForgotten:
		err := q.DeleteDeviceInfoByID(timeout, event.ID)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_remove_info",
				Message: "Failed to remove device info: " + err.Error(),
			})
		}
		_ = q.DeleteDeviceAuth(timeout, event.ID)
		err = q.DeleteDeviceAliasByID(timeout, event.ID)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_remove_aliases",
				Message: "Failed to remove device aliases: " + err.Error(),
			})
		}
		err = q.DeleteDeviceAliasByIDLike(timeout, event.ID+":%")
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_remove_sub_aliases",
				Message: "Failed to remove sub-device aliases: " + err.Error(),
			})
		}
	}
}

func (d *database) HandleCommand(bus *lucifer3.EventBus, command lucifer3.Command) {
	q := mysqlgen.New(d.db)
	timeout, cancel := context.WithTimeout(context.Background(), time.Second/2)
	defer cancel()

	switch command := command.(type) {
	case script.UpdateTrigger:
		err := q.ReplaceScriptTrigger(timeout, mysqlgen.ReplaceScriptTriggerParams{
			ID:           command.ID,
			Event:        string(command.Event),
			DeviceMatch:  command.DeviceMatch,
			Parameter:    command.Parameter,
			ScriptTarget: command.ScriptTarget,
			ScriptName:   command.ScriptName,
			ScriptPre:    toJSON(command.ScriptPre),
			ScriptPost:   toJSON(command.ScriptPost),
			Name:         command.Name,
		})
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_save_trigger",
				Message: "Failed to save trigger: " + err.Error(),
			})
		}
	case script.DeleteTrigger:
		err := q.DeleteScriptTrigger(timeout, command.ID)
		if err != nil {
			bus.RunEvent(events.Log{
				Level:   "error",
				Code:    "database_could_not_delete_trigger",
				Message: "Failed to delete trigger: " + err.Error(),
			})
		}
	case script.SetVariable:
		scopeName := "global"
		if command.Match != nil {
			scopeName = "match:" + *command.Match
		} else if command.Devices != nil {
			scopeName = "devices:" + strings.Join(command.Devices, ";")
		}

		if d.scriptVariables[scopeName+"::"+command.Key] != command.Value {
			d.scriptVariables[scopeName+"::"+command.Key] = command.Value
			err := q.UpdateScriptVariables(timeout, mysqlgen.UpdateScriptVariablesParams{
				Scope: scopeName,
				Name:  command.Key,
				Value: command.Value,
			})
			if err != nil {
				bus.RunEvent(events.Log{
					Level:   "error",
					Code:    "database_could_not_save_variables",
					Message: "Failed to save variable: " + err.Error(),
				})
			}
		}
	case script.Update:
		j, _ := json.Marshal(command.Lines)

		if (len(command.Lines)) > 0 {
			err := q.SaveScript(timeout, mysqlgen.SaveScriptParams{
				Name: command.Name,
				Data: j,
			})
			if err != nil {
				bus.RunEvent(events.Log{
					Level:   "error",
					Code:    "database_could_not_save_script",
					Message: "Failed to save script: " + err.Error(),
				})
			}
		} else {
			err := q.DeleteScript(timeout, command.Name)
			if err != nil {
				bus.RunEvent(events.Log{
					Level:   "error",
					Code:    "database_could_not_delete_script",
					Message: "Failed to delete script: " + err.Error(),
				})
			}
		}
	}
}

func fromJSON[T any](j []byte) T {
	var t T
	_ = json.Unmarshal(j, &t)
	return t
}

func toJSON[T any](v T) json.RawMessage {
	j, _ := json.Marshal(v)
	return j
}

func Connect(host string, port int, username, password, dbname string) (lucifer3.ActiveService, error) {
	db, err := sql.Open("mysql", fmt.Sprintf(
		"%s:%s@(%s:%d)/%s?parseTime=true", username, password, host, port, dbname,
	))
	if err != nil {
		return nil, err
	}

	db.SetMaxOpenConns(10)
	db.SetMaxIdleConns(10)
	db.SetConnMaxIdleTime(time.Minute)

	err = db.Ping()
	if err != nil {
		return nil, err
	}

	return &database{db: db, scriptVariables: make(map[string]string)}, nil
}