package cmd

import (
	"errors"
	"fmt"
	"net/http"
	"os"
	"strings"

	"github.com/golang-migrate/migrate/v4/source"
	"github.com/jessevdk/go-flags"
	"github.com/jmoiron/sqlx"
	"github.com/rs/zerolog"

	"orus.io/orus-io/go-orusapi"
	"orus.io/orus-io/go-orusapi/auth"
	"orus.io/orus-io/go-orusapi/database"
)

var ErrInvalidConfiguration = errors.New("invalid configuration")

type ConfigFile struct {
	ConfigFile string `long:"config" short:"c" env:"CONFIG" no-ini:"t" description:"A configuration file"`
}

//nolint:lll
type InfoOptions struct {
	Environment string `long:"environment" env:"ENVIRONMENT" ini-name:"environment" default:"default" description:"A environment name, used in sentry and prometheus"`
}

type XbusActorFactory struct {
	Name    string
	Factory any
}

type subcommand[E any] struct {
	name string
	init func(*Program[E]) any
}

type Program[E any] struct {
	Version         Version
	BootstrapParser *flags.Parser
	Parser          *flags.Parser

	Logger zerolog.Logger

	ConfigFileOption ConfigFile
	InfoOptions      InfoOptions
	LoggingOptions   *orusapi.LoggingOptions
	TokenOptions     *auth.TokenOptions
	DatabaseOptions  database.Options
	XbusOptions      XbusOptions
	RednerOptions    RednerOptions

	Ext E

	DB *sqlx.DB

	ServeCmd          *ServeCmd[E]
	MigrateCmd        *MigrateCmd[E]
	GenerateConfigCmd *GenerateConfigCmd

	hasDB           bool
	dbMigrateSource source.Driver

	middlewares []Middleware

	setupXbusActors  func(*Program[E]) []XbusActorFactory
	xbusActorNames   []string
	setupHandler     func(*Program[E]) http.Handler
	setupSubcommands []subcommand[E]

	postInit []func(*Program[E])
}

type Option[E any] func(program *Program[E])

func WithHandler[E any](factory func(*Program[E]) http.Handler) Option[E] {
	return func(program *Program[E]) {
		program.setupHandler = factory
	}
}

type Middleware interface {
	Middleware(http.Handler) (http.Handler, error)
}

type middlewareFunc func(http.Handler) (http.Handler, error)

func (f middlewareFunc) Middleware(next http.Handler) (http.Handler, error) {
	return f(next)
}

type middlewareFuncNoErr func(http.Handler) http.Handler

func (f middlewareFuncNoErr) Middleware(next http.Handler) (http.Handler, error) {
	return f(next), nil
}

func WithMiddleware[E any](middleware any) Option[E] {
	var m Middleware
	switch f := middleware.(type) {
	case func(http.Handler) http.Handler:
		m = middlewareFuncNoErr(f)
	case func(http.Handler) (http.Handler, error):
		m = middlewareFunc(f)
	default:
		panic(fmt.Errorf("invalid middleware type: %t", middleware))
	}

	return func(program *Program[E]) {
		program.middlewares = append(program.middlewares, m)
	}
}

func WithXbusActors[E any](factories func(*Program[E]) []XbusActorFactory) Option[E] {
	return func(program *Program[E]) {
		program.setupXbusActors = factories

		g, err := program.Parser.AddGroup("Xbus", "Xbus options", &program.XbusOptions)
		if err != nil {
			panic(err)
		}
		g.Namespace = "xbus"
		g.EnvNamespace = "XBUS"

		SetupXbusCmd(program)
	}
}

func WithTokenOptions[E any]() Option[E] {
	return func(program *Program[E]) {
		program.TokenOptions = auth.NewTokenOptions()
		if _, err := program.Parser.AddGroup("Token", "Token Options", program.TokenOptions); err != nil {
			panic(err)
		}
	}
}

func WithDatabase[E any](migrateSource source.Driver) Option[E] {
	return func(program *Program[E]) {
		program.hasDB = true
		program.dbMigrateSource = migrateSource
	}
}

func WithSubcommand[E any](name string, init func(*Program[E]) any) Option[E] {
	return func(program *Program[E]) {
		program.setupSubcommands = append(program.setupSubcommands, subcommand[E]{
			name: name,
			init: init,
		})
	}
}

type Version struct {
	Version    string
	APIVersion string
	Hash       string
	Branch     string
	HgTopic    string
	Build      string
}

func NewProgram(name string, version Version, options ...Option[struct{}]) *Program[struct{}] {
	return NewProgramWithExt(name, version, struct{}{}, options...)
}

func NewProgramWithExt[E any](name string, version Version, ext E, options ...Option[E]) *Program[E] {
	bootstrapParser := flags.NewNamedParser(name, flags.IgnoreUnknown)
	parser := flags.NewNamedParser(name, flags.HelpFlag|flags.PassDoubleDash)

	program := Program[E]{
		Ext:             ext,
		Version:         version,
		BootstrapParser: bootstrapParser,
		Parser:          parser,
		Logger:          orusapi.DefaultLogger(os.Stdout),
	}

	for _, opt := range options {
		opt(&program)
	}

	program.LoggingOptions = orusapi.MustLoggingOptions(
		orusapi.NewLoggingOptions(&program.Logger, os.Stdout))

	bootstrapParser.NamespaceDelimiter = "-"
	bootstrapParser.EnvNamespaceDelimiter = "_"
	bootstrapParser.EnvNamespace = strings.ToUpper(name)

	if _, err := bootstrapParser.AddGroup(
		"Configuration", "Configuration file", &program.ConfigFileOption,
	); err != nil {
		panic(err)
	}

	if _, err := parser.AddGroup("Configuration", "Configuration file", &program.ConfigFileOption); err != nil {
		panic(err)
	}
	if _, err := parser.AddGroup("Info", "Info options", &program.InfoOptions); err != nil {
		panic(err)
	}

	{
		g, err := parser.AddGroup("Logging", "Logging options", program.LoggingOptions)
		if err != nil {
			panic(err)
		}
		g.Namespace = "log"
		g.EnvNamespace = "LOG"
	}

	program.ServeCmd = SetupServeCmd(&program)
	program.GenerateConfigCmd = SetupGenerateConfigCmd(&program)
	_ = SetupVersionCmd(&program)

	if program.hasDB {
		g, err := parser.AddGroup("Database", "Database options", &program.DatabaseOptions)
		if err != nil {
			panic(err)
		}
		g.Namespace = "db"
		g.EnvNamespace = "DB"

		program.MigrateCmd = SetupMigrateCmd(&program)
	}

	for _, subcmd := range program.setupSubcommands {
		if _, err := parser.AddCommand(subcmd.name, subcmd.name, "", subcmd.init(&program)); err != nil {
			panic(err)
		}
	}

	for _, pi := range program.postInit {
		pi(&program)
	}

	return &program
}

func PostInit[E any](pi func(program *Program[E])) Option[E] {
	return func(program *Program[E]) {
		program.postInit = append(program.postInit, pi)
	}
}

func (program *Program[E]) ParseArgs(args []string) int {
	if _, err := program.BootstrapParser.ParseArgs(args); err != nil {
		program.Logger.Err(err).Msg("could not parse command line")

		return 1
	}
	if program.ConfigFileOption.ConfigFile != "" {
		program.Logger.Debug().Str("configfile", program.ConfigFileOption.ConfigFile).Msg("parsing configuration file")
		iniParser := flags.NewIniParser(program.Parser)
		if err := iniParser.ParseFile(program.ConfigFileOption.ConfigFile); err != nil {
			program.Logger.Err(err).Msg("")

			return 1
		}
	}

	if _, err := program.Parser.Parse(); err != nil {
		code := 1
		var flagsErr *flags.Error
		if errors.As(err, &flagsErr) {
			if flagsErr.Type == flags.ErrHelp {
				code = 0
				// this error actually contains a help message for the user
				// so we print it on the console
				fmt.Println(err)
			} else {
				program.Logger.Error().Msg(err.Error())
			}
		} else {
			program.Logger.Err(err).Msg("")
		}

		return code
	}

	return 0
}

func (program *Program[E]) EnsureDB(automigrate bool) error {
	if !program.hasDB {
		return nil
	}

	program.Logger.Debug().Msg("Connecting to the database...")

	if automigrate {
		if err := database.AutoMigrate(
			program.DatabaseOptions.DSN, program.dbMigrateSource, program.Logger,
		); err != nil {
			return err
		}
	} else {
		if err := database.IsUptodate(
			program.DatabaseOptions.DSN, program.dbMigrateSource,
		); err != nil {
			return err
		}
	}

	db, err := program.DatabaseOptions.Open()
	if err != nil {
		return err
	}

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

	program.DB = db

	program.Logger.Info().Msg("Connected to the database")

	return nil
}

func (program *Program[E]) CloseDB() {
	if !program.hasDB || program.DB == nil {
		return
	}
	if err := program.DB.Close(); err != nil {
		program.Logger.Err(err).Msg("could not close database connection properly")
	}
}