// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package source

import (
	"context"
	"fmt"
	"regexp"
	"strings"
	"sync"
	"time"

	"golang.org/x/tools/go/analysis"
	"golang.org/x/tools/go/analysis/passes/asmdecl"
	"golang.org/x/tools/go/analysis/passes/assign"
	"golang.org/x/tools/go/analysis/passes/atomic"
	"golang.org/x/tools/go/analysis/passes/atomicalign"
	"golang.org/x/tools/go/analysis/passes/bools"
	"golang.org/x/tools/go/analysis/passes/buildtag"
	"golang.org/x/tools/go/analysis/passes/cgocall"
	"golang.org/x/tools/go/analysis/passes/composite"
	"golang.org/x/tools/go/analysis/passes/copylock"
	"golang.org/x/tools/go/analysis/passes/deepequalerrors"
	"golang.org/x/tools/go/analysis/passes/errorsas"
	"golang.org/x/tools/go/analysis/passes/httpresponse"
	"golang.org/x/tools/go/analysis/passes/loopclosure"
	"golang.org/x/tools/go/analysis/passes/lostcancel"
	"golang.org/x/tools/go/analysis/passes/nilfunc"
	"golang.org/x/tools/go/analysis/passes/printf"
	"golang.org/x/tools/go/analysis/passes/shift"
	"golang.org/x/tools/go/analysis/passes/sortslice"
	"golang.org/x/tools/go/analysis/passes/stdmethods"
	"golang.org/x/tools/go/analysis/passes/structtag"
	"golang.org/x/tools/go/analysis/passes/testinggoroutine"
	"golang.org/x/tools/go/analysis/passes/tests"
	"golang.org/x/tools/go/analysis/passes/unmarshal"
	"golang.org/x/tools/go/analysis/passes/unreachable"
	"golang.org/x/tools/go/analysis/passes/unsafeptr"
	"golang.org/x/tools/go/analysis/passes/unusedresult"
	"golang.org/x/tools/internal/lsp/analysis/fillreturns"
	"golang.org/x/tools/internal/lsp/analysis/fillstruct"
	"golang.org/x/tools/internal/lsp/analysis/nonewvars"
	"golang.org/x/tools/internal/lsp/analysis/noresultvalues"
	"golang.org/x/tools/internal/lsp/analysis/simplifycompositelit"
	"golang.org/x/tools/internal/lsp/analysis/simplifyrange"
	"golang.org/x/tools/internal/lsp/analysis/simplifyslice"
	"golang.org/x/tools/internal/lsp/analysis/undeclaredname"
	"golang.org/x/tools/internal/lsp/analysis/unusedparams"
	"golang.org/x/tools/internal/lsp/diff"
	"golang.org/x/tools/internal/lsp/diff/myers"
	"golang.org/x/tools/internal/lsp/protocol"
	errors "golang.org/x/xerrors"
)

var (
	optionsOnce    sync.Once
	defaultOptions *Options
)

//go:generate go run golang.org/x/tools/cmd/stringer -output enums_string.go -type ImportShortcut,HoverKind,Matcher,SymbolMatcher,SymbolStyle
//go:generate go run golang.org/x/tools/internal/lsp/source/genopts -output options_json.go

// DefaultOptions is the options that are used for Gopls execution independent
// of any externally provided configuration (LSP initialization, command
// invokation, etc.).
func DefaultOptions() *Options {
	optionsOnce.Do(func() {
		var commands []string
		for _, c := range Commands {
			commands = append(commands, c.Name)
		}
		defaultOptions = &Options{
			ClientOptions: ClientOptions{
				InsertTextFormat:                  protocol.PlainTextTextFormat,
				PreferredContentFormat:            protocol.Markdown,
				ConfigurationSupported:            true,
				DynamicConfigurationSupported:     true,
				DynamicWatchedFilesSupported:      true,
				LineFoldingOnly:                   false,
				HierarchicalDocumentSymbolSupport: true,
			},
			ServerOptions: ServerOptions{
				SupportedCodeActions: map[FileKind]map[protocol.CodeActionKind]bool{
					Go: {
						protocol.SourceFixAll:          true,
						protocol.SourceOrganizeImports: true,
						protocol.QuickFix:              true,
						protocol.RefactorRewrite:       true,
						protocol.RefactorExtract:       true,
					},
					Mod: {
						protocol.SourceOrganizeImports: true,
					},
					Sum: {},
				},
				SupportedCommands: commands,
			},
			UserOptions: UserOptions{
				HoverKind:  FullDocumentation,
				LinkTarget: "pkg.go.dev",
			},
			DebuggingOptions: DebuggingOptions{
				CompletionBudget:   100 * time.Millisecond,
				LiteralCompletions: true,
			},
			ExperimentalOptions: ExperimentalOptions{
				TempModfile:             true,
				ExpandWorkspaceToModule: true,
				Codelens: map[string]bool{
					CommandGenerate.Name:          true,
					CommandRegenerateCgo.Name:     true,
					CommandTidy.Name:              true,
					CommandToggleDetails.Name:     false,
					CommandUpgradeDependency.Name: true,
					CommandVendor.Name:            true,
				},
				LinksInHover:            true,
				CompleteUnimported:      true,
				CompletionDocumentation: true,
				DeepCompletion:          true,
				Matcher:                 Fuzzy,
				SymbolMatcher:           SymbolFuzzy,
			},
			Hooks: Hooks{
				ComputeEdits:         myers.ComputeEdits,
				URLRegexp:            urlRegexp(),
				DefaultAnalyzers:     defaultAnalyzers(),
				TypeErrorAnalyzers:   typeErrorAnalyzers(),
				ConvenienceAnalyzers: convenienceAnalyzers(),
				StaticcheckAnalyzers: map[string]Analyzer{},
				GoDiff:               true,
			},
		}
	})
	return defaultOptions
}

// Options holds various configuration that affects Gopls execution, organized
// by the nature or origin of the settings.
type Options struct {
	ClientOptions
	ServerOptions
	UserOptions
	DebuggingOptions
	ExperimentalOptions
	Hooks
}

// ClientOptions holds LSP-specific configuration that is provided by the
// client.
type ClientOptions struct {
	InsertTextFormat                  protocol.InsertTextFormat
	ConfigurationSupported            bool
	DynamicConfigurationSupported     bool
	DynamicWatchedFilesSupported      bool
	PreferredContentFormat            protocol.MarkupKind
	LineFoldingOnly                   bool
	HierarchicalDocumentSymbolSupport bool
}

// ServerOptions holds LSP-specific configuration that is provided by the
// server.
type ServerOptions struct {
	SupportedCodeActions map[FileKind]map[protocol.CodeActionKind]bool
	SupportedCommands    []string
}

// UserOptions holds custom Gopls configuration (not part of the LSP) that is
// modified by the client.
type UserOptions struct {
	// BuildFlags is the set of flags passed on to the build system when invoked.
	// It is applied to queries like `go list`, which is used when discovering files.
	// The most common use is to set `-tags`.
	BuildFlags []string

	// Env adds environment variables to external commands run by `gopls`, most notably `go list`.
	Env []string

	// HoverKind controls the information that appears in the hover text.
	// It must be one of:
	// * `"NoDocumentation"`
	// * `"SynopsisDocumentation"`
	// * `"FullDocumentation"`
	//
	// Authors of editor clients may wish to handle hover text differently, and so might use different settings. The options below are not intended for use by anyone other than the authors of editor plugins.
	//
	// * `"SingleLine"`
	// * `"Structured"`
	HoverKind HoverKind

	// Placeholders enables placeholders for function parameters or struct fields in completion responses.
	UsePlaceholders bool

	// LinkTarget controls where documentation links go.
	// It might be one of:
	//
	// * `"godoc.org"`
	// * `"pkg.go.dev"`
	//
	// If company chooses to use its own `godoc.org`, its address can be used as well.
	LinkTarget string

	// Local is the equivalent of the `goimports -local` flag, which puts imports beginning with this string after 3rd-party packages.
	// It should be the prefix of the import path whose imports should be grouped separately.
	Local string

	// Gofumpt indicates if we should run gofumpt formatting.
	Gofumpt bool
}

// Hooks contains configuration that is provided to the Gopls command by the
// main package.
type Hooks struct {
	GoDiff               bool
	ComputeEdits         diff.ComputeEdits
	URLRegexp            *regexp.Regexp
	GofumptFormat        func(ctx context.Context, src []byte) ([]byte, error)
	DefaultAnalyzers     map[string]Analyzer
	TypeErrorAnalyzers   map[string]Analyzer
	ConvenienceAnalyzers map[string]Analyzer
	StaticcheckAnalyzers map[string]Analyzer
}

// ExperimentalOptions defines configuration for features under active
// development. WARNING: This configuration will be changed in the future. It
// only exists while these features are under development.
type ExperimentalOptions struct {
	// Analyses specify analyses that the user would like to enable or disable.
	// A map of the names of analysis passes that should be enabled/disabled.
	// A full list of analyzers that gopls uses can be found [here](analyzers.md)
	//
	// Example Usage:
	// ```json5
	// ...
	// "analyses": {
	//   "unreachable": false, // Disable the unreachable analyzer.
	//   "unusedparams": true  // Enable the unusedparams analyzer.
	// }
	// ...
	// ```
	Analyses map[string]bool

	// Overrides the enabled/disabled state of various code lenses. Currently, we
	// support several code lenses:
	//
	// * `generate`: run `go generate` as specified by a `//go:generate` directive.
	// * `upgrade_dependency`: upgrade a dependency listed in a `go.mod` file.
	// * `test`: run `go test -run` for a test func.
	// * `gc_details`: Show the gc compiler's choices for inline analysis and escaping.
	//
	// Example Usage:
	// ```json5
	// "gopls": {
	// ...
	//   "codelens": {
	//     "generate": false,  // Don't run `go generate`.
	//     "gc_details": true  // Show a code lens toggling the display of gc's choices.
	//   }
	// ...
	// }
	// ```
	Codelens map[string]bool

	// CompletionDocumentation enables documentation with completion results.
	CompletionDocumentation bool

	// CompleteUnimported enables completion for packages that you do not currently import.
	CompleteUnimported bool

	// DeepCompletion If true, this turns on the ability to return completions from deep inside relevant entities, rather than just the locally accessible ones.
	//
	// Consider this example:
	//
	// ```go
	// package main
	//
	// import "fmt"
	//
	// type wrapString struct {
	//     str string
	// }
	//
	// func main() {
	//     x := wrapString{"hello world"}
	//     fmt.Printf(<>)
	// }
	// ```
	//
	// At the location of the `<>` in this program, deep completion would suggest the result `x.str`.
	DeepCompletion bool

	// Matcher sets the algorithm that is used when calculating completion candidates. Must be one of:
	//
	// * `"fuzzy"`
	// * `"caseSensitive"`
	// * `"caseInsensitive"`
	Matcher Matcher

	// Annotations suppress various kinds of optimization diagnostics
	// that would be reported by the gc_details command.
	//   noNilcheck suppresses display of nilchecks.
	//   noEscape suppresses escape choices.
	//   noInline suppresses inlining choices.
	//   noBounds suppresses bounds checking diagnositcs.
	Annotations map[string]bool

	// Staticcheck enables additional analyses from staticcheck.io.
	Staticcheck bool

	// SymbolMatcher sets the algorithm that is used when finding workspace symbols. Must be one of:
	//
	// * `"fuzzy"`
	// * `"caseSensitive"`
	// * `"caseInsensitive"`
	SymbolMatcher SymbolMatcher

	// SymbolStyle specifies what style of symbols to return in symbol requests. Must be one of:
	//
	// * `"full"`
	// * `"dynamic"`
	// * `"package"`
	SymbolStyle SymbolStyle

	// LinksInHover toggles the presence of links to documentation in hover.
	LinksInHover bool

	// TempModfile controls the use of the -modfile flag in Go 1.14.
	TempModfile bool

	// ImportShortcut specifies whether import statements should link to
	// documentation or go to definitions. Must be one of:
	//
	// * `"both"`
	// * `"link"`
	// * `"definition"`
	ImportShortcut ImportShortcut

	// VerboseWorkDoneProgress controls whether the LSP server should send
	// progress reports for all work done outside the scope of an RPC.
	VerboseWorkDoneProgress bool

	// ExpandWorkspaceToModule instructs `gopls` to expand the scope of the workspace to include the
	// modules containing the workspace folders. Set this to false to avoid loading
	// your entire module. This is particularly useful for those working in a monorepo.
	ExpandWorkspaceToModule bool

	// ExperimentalWorkspaceModule opts a user into the experimental support
	// for multi-module workspaces.
	ExperimentalWorkspaceModule bool
}

// DebuggingOptions should not affect the logical execution of Gopls, but may
// be altered for debugging purposes.
type DebuggingOptions struct {
	// VerboseOutput enables additional debug logging.
	VerboseOutput bool

	// CompletionBudget is the soft latency goal for completion requests. Most
	// requests finish in a couple milliseconds, but in some cases deep
	// completions can take much longer. As we use up our budget we
	// dynamically reduce the search scope to ensure we return timely
	// results. Zero means unlimited.
	CompletionBudget time.Duration

	// LiteralCompletions controls whether literal candidates such as
	// "&someStruct{}" are offered. Tests disable this flag to simplify
	// their expected values.
	LiteralCompletions bool
}

type ImportShortcut int

const (
	Both ImportShortcut = iota
	Link
	Definition
)

func (s ImportShortcut) ShowLinks() bool {
	return s == Both || s == Link
}

func (s ImportShortcut) ShowDefinition() bool {
	return s == Both || s == Definition
}

type Matcher int

const (
	Fuzzy = Matcher(iota)
	CaseInsensitive
	CaseSensitive
)

type SymbolMatcher int

const (
	SymbolFuzzy = SymbolMatcher(iota)
	SymbolCaseInsensitive
	SymbolCaseSensitive
)

type SymbolStyle int

const (
	PackageQualifiedSymbols = SymbolStyle(iota)
	FullyQualifiedSymbols
	DynamicSymbols
)

type HoverKind int

const (
	SingleLine = HoverKind(iota)
	NoDocumentation
	SynopsisDocumentation
	FullDocumentation

	// Structured is an experimental setting that returns a structured hover format.
	// This format separates the signature from the documentation, so that the client
	// can do more manipulation of these fields.
	//
	// This should only be used by clients that support this behavior.
	Structured
)

type OptionResults []OptionResult

type OptionResult struct {
	Name  string
	Value interface{}
	Error error

	State       OptionState
	Replacement string
}

type OptionState int

const (
	OptionHandled = OptionState(iota)
	OptionDeprecated
	OptionUnexpected
)

type LinkTarget string

func SetOptions(options *Options, opts interface{}) OptionResults {
	var results OptionResults
	switch opts := opts.(type) {
	case nil:
	case map[string]interface{}:
		for name, value := range opts {
			results = append(results, options.set(name, value))
		}
	default:
		results = append(results, OptionResult{
			Value: opts,
			Error: errors.Errorf("Invalid options type %T", opts),
		})
	}
	return results
}

func (o *Options) ForClientCapabilities(caps protocol.ClientCapabilities) {
	// Check if the client supports snippets in completion items.
	if c := caps.TextDocument.Completion; c.CompletionItem.SnippetSupport {
		o.InsertTextFormat = protocol.SnippetTextFormat
	}
	// Check if the client supports configuration messages.
	o.ConfigurationSupported = caps.Workspace.Configuration
	o.DynamicConfigurationSupported = caps.Workspace.DidChangeConfiguration.DynamicRegistration
	o.DynamicWatchedFilesSupported = caps.Workspace.DidChangeWatchedFiles.DynamicRegistration

	// Check which types of content format are supported by this client.
	if hover := caps.TextDocument.Hover; len(hover.ContentFormat) > 0 {
		o.PreferredContentFormat = hover.ContentFormat[0]
	}
	// Check if the client supports only line folding.
	fr := caps.TextDocument.FoldingRange
	o.LineFoldingOnly = fr.LineFoldingOnly
	// Check if the client supports hierarchical document symbols.
	o.HierarchicalDocumentSymbolSupport = caps.TextDocument.DocumentSymbol.HierarchicalDocumentSymbolSupport
}

func (o *Options) Clone() *Options {
	result := &Options{
		ClientOptions:       o.ClientOptions,
		DebuggingOptions:    o.DebuggingOptions,
		ExperimentalOptions: o.ExperimentalOptions,
		Hooks: Hooks{
			GoDiff:        o.Hooks.GoDiff,
			ComputeEdits:  o.Hooks.ComputeEdits,
			GofumptFormat: o.GofumptFormat,
			URLRegexp:     o.URLRegexp,
		},
		ServerOptions: o.ServerOptions,
		UserOptions:   o.UserOptions,
	}
	// Fully clone any slice or map fields. Only Hooks, ExperimentalOptions,
	// and UserOptions can be modified.
	copyStringMap := func(src map[string]bool) map[string]bool {
		dst := make(map[string]bool)
		for k, v := range src {
			dst[k] = v
		}
		return dst
	}
	result.Analyses = copyStringMap(o.Analyses)
	result.Annotations = copyStringMap(o.Annotations)
	result.Codelens = copyStringMap(o.Codelens)

	copySlice := func(src []string) []string {
		dst := make([]string, len(src))
		copy(dst, src)
		return dst
	}
	result.Env = copySlice(o.Env)
	result.BuildFlags = copySlice(o.BuildFlags)

	copyAnalyzerMap := func(src map[string]Analyzer) map[string]Analyzer {
		dst := make(map[string]Analyzer)
		for k, v := range src {
			dst[k] = v
		}
		return dst
	}
	result.DefaultAnalyzers = copyAnalyzerMap(o.DefaultAnalyzers)
	result.TypeErrorAnalyzers = copyAnalyzerMap(o.TypeErrorAnalyzers)
	result.ConvenienceAnalyzers = copyAnalyzerMap(o.ConvenienceAnalyzers)
	result.StaticcheckAnalyzers = copyAnalyzerMap(o.StaticcheckAnalyzers)
	return result
}

func (options *Options) AddStaticcheckAnalyzer(a *analysis.Analyzer) {
	options.StaticcheckAnalyzers[a.Name] = Analyzer{Analyzer: a, Enabled: true}
}

func (o *Options) set(name string, value interface{}) OptionResult {
	result := OptionResult{Name: name, Value: value}
	switch name {
	case "env":
		menv, ok := value.(map[string]interface{})
		if !ok {
			result.errorf("invalid config gopls.env type %T", value)
			break
		}
		for k, v := range menv {
			o.Env = append(o.Env, fmt.Sprintf("%s=%s", k, v))
		}

	case "buildFlags":
		iflags, ok := value.([]interface{})
		if !ok {
			result.errorf("invalid config gopls.buildFlags type %T", value)
			break
		}
		flags := make([]string, 0, len(iflags))
		for _, flag := range iflags {
			flags = append(flags, fmt.Sprintf("%s", flag))
		}
		o.BuildFlags = flags

	case "completionDocumentation":
		result.setBool(&o.CompletionDocumentation)
	case "usePlaceholders":
		result.setBool(&o.UsePlaceholders)
	case "deepCompletion":
		result.setBool(&o.DeepCompletion)
	case "completeUnimported":
		result.setBool(&o.CompleteUnimported)
	case "completionBudget":
		if v, ok := result.asString(); ok {
			d, err := time.ParseDuration(v)
			if err != nil {
				result.errorf("failed to parse duration %q: %v", v, err)
				break
			}
			o.CompletionBudget = d
		}

	case "matcher":
		matcher, ok := result.asString()
		if !ok {
			break
		}
		switch strings.ToLower(matcher) {
		case "fuzzy":
			o.Matcher = Fuzzy
		case "casesensitive":
			o.Matcher = CaseSensitive
		default:
			o.Matcher = CaseInsensitive
		}

	case "symbolMatcher":
		matcher, ok := result.asString()
		if !ok {
			break
		}
		switch strings.ToLower(matcher) {
		case "fuzzy":
			o.SymbolMatcher = SymbolFuzzy
		case "casesensitive":
			o.SymbolMatcher = SymbolCaseSensitive
		default:
			o.SymbolMatcher = SymbolCaseInsensitive
		}

	case "symbolStyle":
		style, ok := result.asString()
		if !ok {
			break
		}
		switch strings.ToLower(style) {
		case "full":
			o.SymbolStyle = FullyQualifiedSymbols
		case "dynamic":
			o.SymbolStyle = DynamicSymbols
		case "package":
			o.SymbolStyle = PackageQualifiedSymbols
		default:
			result.errorf("Unsupported symbol style %q", style)
		}

	case "hoverKind":
		hoverKind, ok := result.asString()
		if !ok {
			break
		}
		switch strings.ToLower(hoverKind) {
		case "nodocumentation":
			o.HoverKind = NoDocumentation
		case "singleline":
			o.HoverKind = SingleLine
		case "synopsisdocumentation":
			o.HoverKind = SynopsisDocumentation
		case "fulldocumentation":
			o.HoverKind = FullDocumentation
		case "structured":
			o.HoverKind = Structured
		default:
			result.errorf("Unsupported hover kind %q", hoverKind)
		}

	case "linkTarget":
		result.setString(&o.LinkTarget)

	case "linksInHover":
		result.setBool(&o.LinksInHover)

	case "importShortcut":
		var s string
		result.setString(&s)
		switch strings.ToLower(s) {
		case "both":
			o.ImportShortcut = Both
		case "link":
			o.ImportShortcut = Link
		case "definition":
			o.ImportShortcut = Definition
		}

	case "analyses":
		result.setBoolMap(&o.Analyses)

	case "annotations":
		result.setBoolMap(&o.Annotations)
		for k := range o.Annotations {
			switch k {
			case "noEscape", "noNilcheck", "noInline", "noBounds":
				continue
			default:
				result.Name += ":" + k // put mistake(s) in the message
				result.State = OptionUnexpected
			}
		}

	case "codelens":
		var lensOverrides map[string]bool
		result.setBoolMap(&lensOverrides)
		if result.Error == nil {
			if o.Codelens == nil {
				o.Codelens = make(map[string]bool)
			}
			for lens, enabled := range lensOverrides {
				o.Codelens[lens] = enabled
			}
		}

	case "staticcheck":
		result.setBool(&o.Staticcheck)

	case "local":
		result.setString(&o.Local)

	case "verboseOutput":
		result.setBool(&o.VerboseOutput)

	case "verboseWorkDoneProgress":
		result.setBool(&o.VerboseWorkDoneProgress)

	case "tempModfile":
		result.setBool(&o.TempModfile)

	case "gofumpt":
		result.setBool(&o.Gofumpt)

	case "expandWorkspaceToModule":
		result.setBool(&o.ExpandWorkspaceToModule)

	case "experimentalWorkspaceModule":
		result.setBool(&o.ExperimentalWorkspaceModule)

	// Replaced settings.
	case "experimentalDisabledAnalyses":
		result.State = OptionDeprecated
		result.Replacement = "analyses"

	case "disableDeepCompletion":
		result.State = OptionDeprecated
		result.Replacement = "deepCompletion"

	case "disableFuzzyMatching":
		result.State = OptionDeprecated
		result.Replacement = "fuzzyMatching"

	case "wantCompletionDocumentation":
		result.State = OptionDeprecated
		result.Replacement = "completionDocumentation"

	case "wantUnimportedCompletions":
		result.State = OptionDeprecated
		result.Replacement = "completeUnimported"

	case "fuzzyMatching":
		result.State = OptionDeprecated
		result.Replacement = "matcher"

	case "caseSensitiveCompletion":
		result.State = OptionDeprecated
		result.Replacement = "matcher"

	// Deprecated settings.
	case "wantSuggestedFixes":
		result.State = OptionDeprecated

	case "noIncrementalSync":
		result.State = OptionDeprecated

	case "watchFileChanges":
		result.State = OptionDeprecated

	case "go-diff":
		result.State = OptionDeprecated

	default:
		result.State = OptionUnexpected
	}
	return result
}

func (r *OptionResult) errorf(msg string, values ...interface{}) {
	r.Error = errors.Errorf(msg, values...)
}

func (r *OptionResult) asBool() (bool, bool) {
	b, ok := r.Value.(bool)
	if !ok {
		r.errorf("Invalid type %T for bool option %q", r.Value, r.Name)
		return false, false
	}
	return b, true
}

func (r *OptionResult) setBool(b *bool) {
	if v, ok := r.asBool(); ok {
		*b = v
	}
}

func (r *OptionResult) setBoolMap(bm *map[string]bool) {
	all, ok := r.Value.(map[string]interface{})
	if !ok {
		r.errorf("Invalid type %T for map[string]interface{} option %q", r.Value, r.Name)
		return
	}
	m := make(map[string]bool)
	for a, enabled := range all {
		if enabled, ok := enabled.(bool); ok {
			m[a] = enabled
		} else {
			r.errorf("Invalid type %d for map key %q in option %q", a, r.Name)
			return
		}
	}
	*bm = m
}

func (r *OptionResult) asString() (string, bool) {
	b, ok := r.Value.(string)
	if !ok {
		r.errorf("Invalid type %T for string option %q", r.Value, r.Name)
		return "", false
	}
	return b, true
}

func (r *OptionResult) setString(s *string) {
	if v, ok := r.asString(); ok {
		*s = v
	}
}

// EnabledAnalyzers returns all of the analyzers enabled for the given
// snapshot.
func EnabledAnalyzers(snapshot Snapshot) (analyzers []Analyzer) {
	for _, a := range snapshot.View().Options().DefaultAnalyzers {
		if a.IsEnabled(snapshot.View()) {
			analyzers = append(analyzers, a)
		}
	}
	for _, a := range snapshot.View().Options().TypeErrorAnalyzers {
		if a.IsEnabled(snapshot.View()) {
			analyzers = append(analyzers, a)
		}
	}
	for _, a := range snapshot.View().Options().ConvenienceAnalyzers {
		if a.IsEnabled(snapshot.View()) {
			analyzers = append(analyzers, a)
		}
	}
	for _, a := range snapshot.View().Options().StaticcheckAnalyzers {
		if a.IsEnabled(snapshot.View()) {
			analyzers = append(analyzers, a)
		}
	}
	return analyzers
}

func typeErrorAnalyzers() map[string]Analyzer {
	return map[string]Analyzer{
		fillreturns.Analyzer.Name: {
			Analyzer:       fillreturns.Analyzer,
			FixesError:     fillreturns.FixesError,
			HighConfidence: true,
			Enabled:        true,
		},
		nonewvars.Analyzer.Name: {
			Analyzer:   nonewvars.Analyzer,
			FixesError: nonewvars.FixesError,
			Enabled:    true,
		},
		noresultvalues.Analyzer.Name: {
			Analyzer:   noresultvalues.Analyzer,
			FixesError: noresultvalues.FixesError,
			Enabled:    true,
		},
		undeclaredname.Analyzer.Name: {
			Analyzer:   undeclaredname.Analyzer,
			FixesError: undeclaredname.FixesError,
			Command:    CommandUndeclaredName,
			Enabled:    true,
		},
	}
}

func convenienceAnalyzers() map[string]Analyzer {
	return map[string]Analyzer{
		fillstruct.Analyzer.Name: {
			Analyzer: fillstruct.Analyzer,
			Command:  CommandFillStruct,
			Enabled:  true,
		},
	}
}

func defaultAnalyzers() map[string]Analyzer {
	return map[string]Analyzer{
		// The traditional vet suite:
		asmdecl.Analyzer.Name:      {Analyzer: asmdecl.Analyzer, Enabled: true},
		assign.Analyzer.Name:       {Analyzer: assign.Analyzer, Enabled: true},
		atomic.Analyzer.Name:       {Analyzer: atomic.Analyzer, Enabled: true},
		atomicalign.Analyzer.Name:  {Analyzer: atomicalign.Analyzer, Enabled: true},
		bools.Analyzer.Name:        {Analyzer: bools.Analyzer, Enabled: true},
		buildtag.Analyzer.Name:     {Analyzer: buildtag.Analyzer, Enabled: true},
		cgocall.Analyzer.Name:      {Analyzer: cgocall.Analyzer, Enabled: true},
		composite.Analyzer.Name:    {Analyzer: composite.Analyzer, Enabled: true},
		copylock.Analyzer.Name:     {Analyzer: copylock.Analyzer, Enabled: true},
		errorsas.Analyzer.Name:     {Analyzer: errorsas.Analyzer, Enabled: true},
		httpresponse.Analyzer.Name: {Analyzer: httpresponse.Analyzer, Enabled: true},
		loopclosure.Analyzer.Name:  {Analyzer: loopclosure.Analyzer, Enabled: true},
		lostcancel.Analyzer.Name:   {Analyzer: lostcancel.Analyzer, Enabled: true},
		nilfunc.Analyzer.Name:      {Analyzer: nilfunc.Analyzer, Enabled: true},
		printf.Analyzer.Name:       {Analyzer: printf.Analyzer, Enabled: true},
		shift.Analyzer.Name:        {Analyzer: shift.Analyzer, Enabled: true},
		stdmethods.Analyzer.Name:   {Analyzer: stdmethods.Analyzer, Enabled: true},
		structtag.Analyzer.Name:    {Analyzer: structtag.Analyzer, Enabled: true},
		tests.Analyzer.Name:        {Analyzer: tests.Analyzer, Enabled: true},
		unmarshal.Analyzer.Name:    {Analyzer: unmarshal.Analyzer, Enabled: true},
		unreachable.Analyzer.Name:  {Analyzer: unreachable.Analyzer, Enabled: true},
		unsafeptr.Analyzer.Name:    {Analyzer: unsafeptr.Analyzer, Enabled: true},
		unusedresult.Analyzer.Name: {Analyzer: unusedresult.Analyzer, Enabled: true},

		// Non-vet analyzers:
		deepequalerrors.Analyzer.Name:  {Analyzer: deepequalerrors.Analyzer, Enabled: true},
		sortslice.Analyzer.Name:        {Analyzer: sortslice.Analyzer, Enabled: true},
		testinggoroutine.Analyzer.Name: {Analyzer: testinggoroutine.Analyzer, Enabled: true},
		unusedparams.Analyzer.Name:     {Analyzer: unusedparams.Analyzer, Enabled: false},

		// gofmt -s suite:
		simplifycompositelit.Analyzer.Name: {Analyzer: simplifycompositelit.Analyzer, Enabled: true, HighConfidence: true},
		simplifyrange.Analyzer.Name:        {Analyzer: simplifyrange.Analyzer, Enabled: true, HighConfidence: true},
		simplifyslice.Analyzer.Name:        {Analyzer: simplifyslice.Analyzer, Enabled: true, HighConfidence: true},
	}
}

func urlRegexp() *regexp.Regexp {
	// Ensure links are matched as full words, not anywhere.
	re := regexp.MustCompile(`\b(http|ftp|https)://([\w_-]+(?:(?:\.[\w_-]+)+))([\w.,@?^=%&:/~+#-]*[\w@?^=%&/~+#-])?\b`)
	re.Longest()
	return re
}