// Copyright 2020-2025 Buf Technologies, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package bufanalysis

import (
	"fmt"
	"io"
	"strconv"
	"strings"
)

const (
	// FormatText is the text format for FileAnnotations.
	FormatText Format = iota + 1
	// FormatJSON is the JSON format for FileAnnotations.
	FormatJSON
	// FormatMSVS is the MSVS format for FileAnnotations.
	FormatMSVS
	// FormatJUnit is the JUnit format for FileAnnotations.
	FormatJUnit
	// FormatGithubActions is the Github Actions format for FileAnnotations.
	//
	// See https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-an-error-message.
	FormatGithubActions
)

var (
	// AllFormatStrings is all format strings without aliases.
	//
	// Sorted in the order we want to display them.
	AllFormatStrings = []string{
		"text",
		"json",
		"msvs",
		"junit",
		"github-actions",
	}
	// AllFormatStringsWithAliases is all format strings with aliases.
	//
	// Sorted in the order we want to display them.
	AllFormatStringsWithAliases = []string{
		"text",
		"gcc",
		"json",
		"msvs",
		"junit",
		"github-actions",
	}

	stringToFormat = map[string]Format{
		"text": FormatText,
		// alias for text
		"gcc":            FormatText,
		"json":           FormatJSON,
		"msvs":           FormatMSVS,
		"junit":          FormatJUnit,
		"github-actions": FormatGithubActions,
	}
	formatToString = map[Format]string{
		FormatText:          "text",
		FormatJSON:          "json",
		FormatMSVS:          "msvs",
		FormatJUnit:         "junit",
		FormatGithubActions: "github-actions",
	}
)

// Format is a FileAnnotation format.
type Format int

// String implements fmt.Stringer.
func (f Format) String() string {
	s, ok := formatToString[f]
	if !ok {
		return strconv.Itoa(int(f))
	}
	return s
}

// ParseFormat parses the Format.
//
// The empty strings defaults to FormatText.
func ParseFormat(s string) (Format, error) {
	s = strings.ToLower(strings.TrimSpace(s))
	if s == "" {
		return FormatText, nil
	}
	f, ok := stringToFormat[s]
	if ok {
		return f, nil
	}
	return 0, fmt.Errorf("unknown format: %q", s)
}

// FileInfo is a minimal FileInfo interface.
type FileInfo interface {
	Path() string
	ExternalPath() string
}

// FileAnnotation is a file annotation.
type FileAnnotation interface {
	// Stringer returns the string representation for this FileAnnotation.
	fmt.Stringer

	// FileInfo is the FileInfo for this annotation.
	//
	// This may be nil.
	FileInfo() FileInfo

	// StartLine is the starting line.
	//
	// If the starting line is not known, this will be 0.
	StartLine() int
	// StartColumn is the starting column.
	//
	// If the starting column is not known, this will be 0.
	StartColumn() int
	// EndLine is the ending line.
	//
	// If the ending line is not known, this will be 0.
	// If the ending line is the same as the starting line, this will be explicitly
	// set to the same value as start_line.
	EndLine() int
	// EndColumn is the ending column.
	//
	// If the ending column is not known, this will be 0.
	// If the ending column is the same as the starting column, this will be explicitly
	// set to the same value as start_column.
	EndColumn() int
	// Type is the type of annotation, typically an ID representing a failure type.
	Type() string
	// Message is the message of the annotation.
	Message() string
	// PluginName is the name of the plugin that the annotation originated from.
	//
	// May be empty if this annotation did not originate from a plugin.
	// This may be added to the printed message field for certain printers.
	PluginName() string
	// PolicyName is the name of the policy that the annotation originated from.
	//
	// May be empty if this annotation did not originate from a policy.
	// This may be added to the printed message field for certain printers.
	PolicyName() string

	isFileAnnotation()
}

// NewFileAnnotation returns a new FileAnnotation.
func NewFileAnnotation(
	fileInfo FileInfo,
	startLine int,
	startColumn int,
	endLine int,
	endColumn int,
	typeString string,
	message string,
	pluginName string,
	policyName string,
) FileAnnotation {
	return newFileAnnotation(
		fileInfo,
		startLine,
		startColumn,
		endLine,
		endColumn,
		typeString,
		message,
		pluginName,
		policyName,
	)
}

// FileAnnotationSet is a set of FileAnnotations.
type FileAnnotationSet interface {
	// Stringer returns the string representation for this FileAnnotationSet.
	fmt.Stringer
	// error returns an error for this FileAnnotationSet. It will use the text format
	// to create an error message.
	error

	// FileAnnotations returns the FileAnnotations in the set.
	//
	// This will always be non-empty.
	// These will be deduplicated and sorted.
	FileAnnotations() []FileAnnotation

	isFileAnnotationSet()
}

// NewFileAnnotationSet returns a new FileAnnotationSet.
//
// If len(fileAnnotations) is 0, this returns nil.
func NewFileAnnotationSet(fileAnnotations ...FileAnnotation) FileAnnotationSet {
	return newFileAnnotationSet(fileAnnotations)
}

// PrintFileAnnotationSet prints the file annotations separated by newlines.
func PrintFileAnnotationSet(writer io.Writer, fileAnnotationSet FileAnnotationSet, formatString string) error {
	format, err := ParseFormat(formatString)
	if err != nil {
		return err
	}

	switch format {
	case FormatText:
		return printAsText(writer, fileAnnotationSet.FileAnnotations())
	case FormatJSON:
		return printAsJSON(writer, fileAnnotationSet.FileAnnotations())
	case FormatMSVS:
		return printAsMSVS(writer, fileAnnotationSet.FileAnnotations())
	case FormatJUnit:
		return printAsJUnit(writer, fileAnnotationSet.FileAnnotations())
	case FormatGithubActions:
		return printAsGithubActions(writer, fileAnnotationSet.FileAnnotations())
	default:
		return fmt.Errorf("unknown FileAnnotation Format: %v", format)
	}
}
