package paramParser

import (
	"fmt"
	"log/slog"
	"net/url"
	"strconv"
	"time"
)

type ParamsParser struct {
	urlParams url.Values
}

type NoValueError struct {
	Key string
}

func (e *NoValueError) Error() string {
	return fmt.Sprintf("No value found for key %s", e.Key)
}

func New(_urlParams url.Values) ParamsParser {
	return ParamsParser{
		urlParams: _urlParams,
	}
}

func (p *ParamsParser) ParseTimestampFallback(key string, format string, fallback time.Time) time.Time {
	if !p.urlParams.Has(key) {
		return fallback
	}
	paramTimestamp := p.urlParams.Get(key)
	if timestamp, err := time.Parse(format, paramTimestamp); err == nil {
		return timestamp
	} else {
		slog.Warn("Error parsing HTTP Params to time.Time", slog.Any("key", key), slog.Any("error", err))
		return fallback
	}
}

func (p *ParamsParser) ParseTimestamp(key string, format string) (time.Time, error) {
	if !p.urlParams.Has(key) {
		return time.Time{}, &NoValueError{Key: key}
	}
	paramTimestamp := p.urlParams.Get(key)
	if timestamp, err := time.Parse(format, paramTimestamp); err == nil {
		return timestamp, nil
	} else {
		slog.Debug("Error parsing HTTP Params to time.Time", slog.Any("key", key), slog.Any("error", err))
		return timestamp, err
	}
}

func (p *ParamsParser) ParseStringFallback(key string, fallback string) string {
	if !p.urlParams.Has(key) {
		return fallback
	}
	return p.urlParams.Get(key)
}

func (p *ParamsParser) ParseString(key string, fallback string) (string, error) {
	if !p.urlParams.Has(key) {
		return "", &NoValueError{Key: key}
	}
	return p.urlParams.Get(key), nil
}

func (p *ParamsParser) ParseIntFallback(key string, fallback int) int {
	if !p.urlParams.Has(key) {
		return fallback
	}
	paramInt := p.urlParams.Get(key)
	if result, err := strconv.Atoi(paramInt); err == nil {
		return result
	} else {
		slog.Warn("Error parsing HTTP Params to Int", slog.Any("key", key), slog.Any("error", err))
		return fallback
	}
}

func (p *ParamsParser) ParseInt(key string) (int, error) {
	if !p.urlParams.Has(key) {
		return 0, &NoValueError{Key: key}
	}
	paramInt := p.urlParams.Get(key)
	if result, err := strconv.Atoi(paramInt); err == nil {
		return result, nil
	} else {
		slog.Debug("Error parsing HTTP Params to Int", slog.Any("key", key), slog.Any("error", err))
		return 0, err
	}
}