package types

import (
	"fmt"
	"strings"

	sdk "github.com/cosmos/cosmos-sdk/types"
)

// Constants pertaining to a Content object
const (
	MaxDescriptionLength int = 5000
	MaxTitleLength       int = 140
)

// Content defines an interface that a proposal must implement. It contains
// information such as the title and description along with the type and routing
// information for the appropriate handler to process the proposal. Content can
// have additional fields, which will handled by a proposal's Handler.
type Content interface {
	GetTitle() string
	GetDescription() string
	ProposalRoute() string
	ProposalType() string
	ValidateBasic() sdk.Error
	String() string
}

// Handler defines a function that handles a proposal after it has passed the
// governance process.
type Handler func(ctx sdk.Context, content Content) sdk.Error

// ValidateAbstract validates a proposal's abstract contents returning an error
// if invalid.
func ValidateAbstract(codespace sdk.CodespaceType, c Content) sdk.Error {
	title := c.GetTitle()
	if len(strings.TrimSpace(title)) == 0 {
		return ErrInvalidProposalContent(codespace, "proposal title cannot be blank")
	}
	if len(title) > MaxTitleLength {
		return ErrInvalidProposalContent(codespace, fmt.Sprintf("proposal title is longer than max length of %d", MaxTitleLength))
	}

	description := c.GetDescription()
	if len(description) == 0 {
		return ErrInvalidProposalContent(codespace, "proposal description cannot be blank")
	}
	if len(description) > MaxDescriptionLength {
		return ErrInvalidProposalContent(codespace, fmt.Sprintf("proposal description is longer than max length of %d", MaxDescriptionLength))
	}

	return nil
}