package codersdk

import (
	"golang.org/x/xerrors"

	"github.com/coder/terraform-provider-coder/provider"
)

func ValidateWorkspaceBuildParameters(richParameters []TemplateVersionParameter, buildParameters []WorkspaceBuildParameter) error {
	for _, buildParameter := range buildParameters {
		if buildParameter.Name == "" {
			return xerrors.Errorf(`workspace build parameter name is missing`)
		}
		richParameter, found := findTemplateVersionParameter(richParameters, buildParameter.Name)
		if !found {
			return xerrors.Errorf(`workspace build parameter is not defined in the template ("coder_parameter"): %s`, buildParameter.Name)
		}

		err := ValidateWorkspaceBuildParameter(*richParameter, buildParameter)
		if err != nil {
			return xerrors.Errorf("can't validate build parameter %q: %w", buildParameter.Name, err)
		}
	}
	return nil
}

func ValidateWorkspaceBuildParameter(richParameter TemplateVersionParameter, buildParameter WorkspaceBuildParameter) error {
	value := buildParameter.Value
	if value == "" {
		value = richParameter.DefaultValue
	}

	if len(richParameter.Options) > 0 {
		var matched bool
		for _, opt := range richParameter.Options {
			if opt.Value == value {
				matched = true
				break
			}
		}

		if !matched {
			return xerrors.Errorf("parameter value must match one of options: %s", parameterValuesAsArray(richParameter.Options))
		}
		return nil
	}

	if !validationEnabled(richParameter) {
		return nil
	}

	validation := &provider.Validation{
		Min:   int(richParameter.ValidationMin),
		Max:   int(richParameter.ValidationMax),
		Regex: richParameter.ValidationRegex,
		Error: richParameter.ValidationError,
	}
	return validation.Valid(richParameter.Type, value)
}

func findTemplateVersionParameter(params []TemplateVersionParameter, parameterName string) (*TemplateVersionParameter, bool) {
	for _, p := range params {
		if p.Name == parameterName {
			return &p, true
		}
	}
	return nil, false
}

func parameterValuesAsArray(options []TemplateVersionParameterOption) []string {
	var arr []string
	for _, opt := range options {
		arr = append(arr, opt.Value)
	}
	return arr
}

func validationEnabled(param TemplateVersionParameter) bool {
	return len(param.ValidationRegex) > 0 ||
		(param.ValidationMin != 0 && param.ValidationMax != 0) ||
		param.Type == "bool" // boolean type doesn't have any custom validation rules, but the value must be checked (true/false).
}