package parser

import (
	"errors"
	"fmt"
	"net/url"
	"os"
	"time"

	"github.com/aykhans/dodo/pkg/config"
	"github.com/aykhans/dodo/pkg/types"
	"github.com/aykhans/dodo/pkg/utils"
)

var _ IParser = ConfigENVParser{}

type ConfigENVParser struct {
	envPrefix string
}

func NewConfigENVParser(envPrefix string) *ConfigENVParser {
	return &ConfigENVParser{envPrefix}
}

// Parse parses env arguments into a Config object.
// It can return the following errors:
// - types.FieldParseErrors
func (parser ConfigENVParser) Parse() (*config.Config, error) {
	var (
		config           = &config.Config{}
		fieldParseErrors []types.FieldParseError
	)

	if configFile := parser.getEnv("CONFIG_FILE"); configFile != "" {
		configFileParsed, err := types.ParseConfigFile(configFile)

		_ = utils.HandleErrorOrDie(err,
			utils.OnSentinelError(types.ErrConfigFileExtensionNotFound, func(err error) error {
				fieldParseErrors = append(
					fieldParseErrors,
					*types.NewFieldParseError(
						parser.getFullEnvName("CONFIG_FILE"),
						configFile,
						errors.New("file extension not found"),
					),
				)
				return nil
			}),
			utils.OnCustomError(func(err types.RemoteConfigFileParseError) error {
				fieldParseErrors = append(
					fieldParseErrors,
					*types.NewFieldParseError(
						parser.getFullEnvName("CONFIG_FILE"),
						configFile,
						fmt.Errorf("parse error: %w", err),
					),
				)
				return nil
			}),
			utils.OnCustomError(func(err types.UnknownConfigFileTypeError) error {
				fieldParseErrors = append(
					fieldParseErrors,
					*types.NewFieldParseError(
						parser.getFullEnvName("CONFIG_FILE"),
						configFile,
						fmt.Errorf("file type '%s' not supported (supported types: %s)", err.Type, types.ConfigFileTypeYAML),
					),
				)
				return nil
			}),
		)

		if err == nil {
			config.Files = append(config.Files, *configFileParsed)
		}
	}

	if yes := parser.getEnv("YES"); yes != "" {
		yesParsed, err := utils.ParseString[bool](yes)
		if err != nil {
			fieldParseErrors = append(
				fieldParseErrors,
				*types.NewFieldParseError(
					parser.getFullEnvName("YES"),
					yes,
					errors.New("invalid value for boolean, expected 'true' or 'false'"),
				),
			)
		} else {
			config.Yes = &yesParsed
		}
	}

	if skipVerify := parser.getEnv("SKIP_VERIFY"); skipVerify != "" {
		skipVerifyParsed, err := utils.ParseString[bool](skipVerify)
		if err != nil {
			fieldParseErrors = append(
				fieldParseErrors,
				*types.NewFieldParseError(
					parser.getFullEnvName("SKIP_VERIFY"),
					skipVerify,
					errors.New("invalid value for boolean, expected 'true' or 'false'"),
				),
			)
		} else {
			config.SkipVerify = &skipVerifyParsed
		}
	}

	if method := parser.getEnv("METHOD"); method != "" {
		config.Method = &method
	}

	if urlEnv := parser.getEnv("URL"); urlEnv != "" {
		urlEnvParsed, err := url.Parse(urlEnv)
		if err != nil {
			fieldParseErrors = append(
				fieldParseErrors,
				*types.NewFieldParseError(parser.getFullEnvName("URL"), urlEnv, err),
			)
		} else {
			config.URL = urlEnvParsed
		}
	}

	if dodos := parser.getEnv("DODOS"); dodos != "" {
		dodosParsed, err := utils.ParseString[uint](dodos)
		if err != nil {
			fieldParseErrors = append(
				fieldParseErrors,
				*types.NewFieldParseError(
					parser.getFullEnvName("DODOS"),
					dodos,
					errors.New("invalid value for unsigned integer"),
				),
			)
		} else {
			config.DodosCount = &dodosParsed
		}
	}

	if requests := parser.getEnv("REQUESTS"); requests != "" {
		requestsParsed, err := utils.ParseString[uint](requests)
		if err != nil {
			fieldParseErrors = append(
				fieldParseErrors,
				*types.NewFieldParseError(
					parser.getFullEnvName("REQUESTS"),
					requests,
					errors.New("invalid value for unsigned integer"),
				),
			)
		} else {
			config.RequestCount = &requestsParsed
		}
	}

	if duration := parser.getEnv("DURATION"); duration != "" {
		durationParsed, err := utils.ParseString[time.Duration](duration)
		if err != nil {
			fieldParseErrors = append(
				fieldParseErrors,
				*types.NewFieldParseError(
					parser.getFullEnvName("DURATION"),
					duration,
					errors.New("invalid value duration, expected a duration string (e.g., '10s', '1h30m')"),
				),
			)
		} else {
			config.Duration = &durationParsed
		}
	}

	if timeout := parser.getEnv("TIMEOUT"); timeout != "" {
		timeoutParsed, err := utils.ParseString[time.Duration](timeout)
		if err != nil {
			fieldParseErrors = append(
				fieldParseErrors,
				*types.NewFieldParseError(
					parser.getFullEnvName("TIMEOUT"),
					timeout,
					errors.New("invalid value duration, expected a duration string (e.g., '10s', '1h30m')"),
				),
			)
		} else {
			config.Timeout = &timeoutParsed
		}
	}

	if param := parser.getEnv("PARAM"); param != "" {
		config.Params.Parse(param)
	}

	if header := parser.getEnv("HEADER"); header != "" {
		config.Headers.Parse(header)
	}

	if cookie := parser.getEnv("COOKIE"); cookie != "" {
		config.Cookies.Parse(cookie)
	}

	if body := parser.getEnv("BODY"); body != "" {
		config.Bodies.Parse(body)
	}

	if proxy := parser.getEnv("PROXY"); proxy != "" {
		err := config.Proxies.Parse(proxy)
		if err != nil {
			fieldParseErrors = append(
				fieldParseErrors,
				*types.NewFieldParseError(
					parser.getFullEnvName("PROXY"),
					proxy,
					err,
				),
			)
		}
	}

	if len(fieldParseErrors) > 0 {
		return nil, types.NewFieldParseErrors(fieldParseErrors)
	}

	return config, nil
}

func (parser ConfigENVParser) getFullEnvName(envName string) string {
	if parser.envPrefix == "" {
		return envName
	}
	return parser.envPrefix + "_" + envName
}

func (parser ConfigENVParser) getEnv(envName string) string {
	return os.Getenv(parser.getFullEnvName(envName))
}