peco.peco/interface.go

package peco

import (
	"io"
	"sync"
	"time"

	"context"

	"github.com/google/btree"
	"github.com/nsf/termbox-go"
	"github.com/peco/peco/filter"
	"github.com/peco/peco/hub"
	"github.com/peco/peco/internal/keyseq"
	"github.com/peco/peco/line"
	"github.com/peco/peco/pipeline"
)

const (
	successKey = "success"
	errorKey   = "error"
)

const (
	ToLineAbove       PagingRequestType = iota // ToLineAbove moves the selection to the line above
	ToScrollPageDown                           // ToScrollPageDown moves the selection to the next page
	ToLineBelow                                // ToLineBelow moves the selection to the line below
	ToScrollPageUp                             // ToScrollPageUp moves the selection to the previous page
	ToScrollLeft                               // ToScrollLeft scrolls screen to the left
	ToScrollRight                              // ToScrollRight scrolls screen to the right
	ToLineInPage                               // ToLineInPage jumps to a particular line on the page
	ToScrollFirstItem                          // ToScrollFirstItem
	ToScrollLastItem                           // ToScrollLastItem
)

const (
	DefaultLayoutType  = LayoutTypeTopDown // LayoutTypeTopDown makes the layout so the items read from top to bottom
	LayoutTypeTopDown  = "top-down"        // LayoutTypeBottomUp changes the layout to read from bottom to up
	LayoutTypeBottomUp = "bottom-up"
)

const (
	AnchorTop    VerticalAnchor = iota + 1 // AnchorTop anchors elements towards the top of the screen
	AnchorBottom                           // AnchorBottom anchors elements towards the bottom of the screen
)

// These are used as keys in the config file
const (
	IgnoreCaseMatch    = "IgnoreCase"
	CaseSensitiveMatch = "CaseSensitive"
	SmartCaseMatch     = "SmartCase"
	RegexpMatch        = "Regexp"
)

const (
	OnEmptyExit = `exit`
)

type idgen struct {
	ch chan uint64
}

// Peco is the global object containing everything required to run peco.
// It also contains the global state of the program.
type Peco struct {
	Argv   []string
	Stdin  io.Reader
	Stdout io.Writer
	Stderr io.Writer
	hub    MessageHub

	args       []string
	bufferSize int
	caret      Caret
	// Config contains the values read in from config file
	config                  Config
	currentLineBuffer       Buffer
	enableSep               bool // Enable parsing on separators
	execOnFinish            string
	filters                 filter.Set
	idgen                   *idgen
	initialFilter           string
	initialQuery            string   // populated if --query is specified
	inputseq                Inputseq // current key sequence (just the names)
	keymap                  Keymap
	layoutType              string
	location                Location
	maxScanBufferSize       int
	mutex                   sync.Mutex
	onCancel                string
	onEmpty                 string
	printQuery              bool
	prompt                  string
	query                   Query
	queryExecDelay          time.Duration
	queryExecMutex          sync.Mutex
	queryExecTimer          *time.Timer
	readyCh                 chan struct{}
	resultCh                chan line.Line
	screen                  Screen
	selection               *Selection
	selectionPrefix         string
	selectionRangeStart     RangeStart
	selectOneAndExit        bool // True if --select-1 is enabled
	singleKeyJumpMode       bool
	singleKeyJumpPrefixes   []rune
	singleKeyJumpPrefixMap  map[rune]uint
	singleKeyJumpShowPrefix bool
	skipReadConfig          bool
	styles                  StyleSet
	use256Color             bool

	// Source is where we buffer input. It gets reused when a new query is
	// executed.
	source *Source

	// cancelFunc is called for Exit()
	cancelFunc func()
	// Errors are stored here
	err error
}

type MatchIndexer interface {
	// Indices return the matched portion(s) of a string after filtering.
	// Note that while Indices may return nil, that just means that there are
	// no substrings to be highlighted. It doesn't mean there were no matches
	Indices() [][]int
}

type Keyseq interface {
	Add(keyseq.KeyList, interface{})
	AcceptKey(keyseq.Key) (interface{}, error)
	CancelChain()
	Clear()
	Compile() error
	InMiddleOfChain() bool
}

// PagingRequest can be sent to move the selection cursor
type PagingRequestType int

type PagingRequest interface {
	Type() PagingRequestType
}

type JumpToLineRequest int

// Selection stores the line ids that were selected by the user.
// The contents of the Selection is always sorted from smallest to
// largest line ID
type Selection struct {
	mutex sync.Mutex
	tree  *btree.BTree
}

// Screen hides termbox from the consuming code so that
// it can be swapped out for testing
type Screen interface {
	Init(*Config) error
	Close() error
	Flush() error
	PollEvent(context.Context, *Config) chan termbox.Event
	Print(PrintArgs) int
	Resume()
	SetCell(int, int, rune, termbox.Attribute, termbox.Attribute)
	SetCursor(int, int)
	Size() (int, int)
	SendEvent(termbox.Event)
	Suspend()
}

// Termbox just hands out the processing to the termbox library
type Termbox struct {
	mutex     sync.Mutex
	resumeCh  chan chan struct{}
	suspendCh chan struct{}
}

// View handles the drawing/updating the screen
type View struct {
	layout Layout
	state  *Peco
}

// PageCrop filters out a new LineBuffer based on entries
// per page and the page number
type PageCrop struct {
	perPage     int
	currentPage int
}

// LayoutType describes the types of layout that peco can take
type LayoutType string

// VerticalAnchor describes the direction to which elements in the
// layout are anchored to
type VerticalAnchor int

// Layout represents the component that controls where elements are placed on screen
type Layout interface {
	PrintStatus(string, time.Duration)
	DrawPrompt(*Peco)
	DrawScreen(*Peco, *DrawOptions)
	MovePage(*Peco, PagingRequest) (moved bool)
	PurgeDisplayCache()
}

// AnchorSettings groups items that are required to control
// where an anchored item is actually placed
type AnchorSettings struct {
	anchor       VerticalAnchor // AnchorTop or AnchorBottom
	anchorOffset int            // offset this many lines from the anchor
	screen       Screen
}

// UserPrompt draws the prompt line
type UserPrompt struct {
	*AnchorSettings
	prompt    string
	promptLen int
	styles    *StyleSet
}

// StatusBar draws the status message bar
type StatusBar struct {
	*AnchorSettings
	clearTimer *time.Timer
	styles     *StyleSet
	timerMutex sync.Mutex
}

// ListArea represents the area where the actual line buffer is
// displayed in the screen
type ListArea struct {
	*AnchorSettings
	sortTopDown  bool
	displayCache []line.Line
	dirty        bool
	styles       *StyleSet
}

// BasicLayout is... the basic layout :) At this point this is the
// only struct for layouts, which means that while the position
// of components may be configurable, the actual types of components
// that are used are set and static
type BasicLayout struct {
	*StatusBar
	prompt *UserPrompt
	list   *ListArea
}

// Keymap holds all the key sequence to action map
type Keymap struct {
	Config map[string]string
	Action map[string][]string // custom actions
	seq    Keyseq
}

// Filter is responsible for the actual "grep" part of peco
type Filter struct {
	state *Peco
}

// Action describes an action that can be executed upon receiving user
// input. It's an interface so you can create any kind of Action you need,
// but most everything is implemented in terms of ActionFunc, which is
// callback based Action
type Action interface {
	Register(string, ...termbox.Key)
	RegisterKeySequence(string, keyseq.KeyList)
	Execute(context.Context, *Peco, termbox.Event)
}

// ActionFunc is a type of Action that is basically just a callback.
type ActionFunc func(context.Context, *Peco, termbox.Event)

// FilteredBuffer holds a "filtered" buffer. It holds a reference to
// the source buffer (note: should be immutable) and a list of indices
// into the source buffer
type FilteredBuffer struct {
	maxcols   int
	src       Buffer
	selection []int // maps from our index to src's index
}

// Config holds all the data that can be configured in the
// external configuration file
type Config struct {
	Action map[string][]string `json:"Action"`
	// Keymap used to be directly responsible for dispatching
	// events against user input, but since then this has changed
	// into something that just records the user's config input
	Keymap              map[string]string `json:"Keymap"`
	Matcher             string            `json:"Matcher"`        // Deprecated.
	InitialMatcher      string            `json:"InitialMatcher"` // Use this instead of Matcher
	InitialFilter       string            `json:"InitialFilter"`
	Style               StyleSet          `json:"Style"`
	Prompt              string            `json:"Prompt"`
	Layout              string            `json:"Layout"`
	Use256Color         bool              `json:"Use256Color"`
	OnCancel            string            `json:"OnCancel"`
	CustomMatcher       map[string][]string
	CustomFilter        map[string]CustomFilterConfig
	QueryExecutionDelay int
	StickySelection     bool
	MaxScanBufferSize   int

	// If this is true, then the prefix for single key jump mode
	// is displayed by default.
	SingleKeyJump SingleKeyJumpConfig `json:"SingleKeyJump"`

	// Use this prefix to denote currently selected line
	SelectionPrefix string `json:"SelectionPrefix"`
}

type SingleKeyJumpConfig struct {
	ShowPrefix bool `json:"ShowPrefix"`
}

// CustomFilterConfig is used to specify configuration parameters
// to CustomFilters
type CustomFilterConfig struct {
	// Cmd is the name of the command to invoke
	Cmd string

	// TODO: need to check if how we use this is correct
	Args []string

	// BufferThreshold defines how many lines peco buffers before
	// invoking the external command. If this value is big, we
	// will execute the external command fewer times, but the
	// results will not be generated for longer periods of time.
	// If this value is small, we will execute the external command
	// more often, but you pay the penalty of invoking that command
	// more times.
	BufferThreshold int
}

// StyleSet holds styles for various sections
type StyleSet struct {
	Basic          Style `json:"Basic"`
	SavedSelection Style `json:"SavedSelection"`
	Selected       Style `json:"Selected"`
	Query          Style `json:"Query"`
	Matched        Style `json:"Matched"`
}

// Style describes termbox styles
type Style struct {
	fg termbox.Attribute
	bg termbox.Attribute
}

type Caret struct {
	mutex sync.Mutex
	pos   int
}

type Location struct {
	col     int
	lineno  int
	maxPage int
	page    int
	perPage int
	offset  int
	total   int
}

type Query struct {
	query      []rune
	savedQuery []rune
	mutex      sync.Mutex
}

type FilterQuery Query

// Source implements pipeline.Source, and is the buffer for the input
type Source struct {
	pipeline.ChanOutput

	capacity   int
	enableSep  bool
	idgen      line.IDGenerator
	in         io.Reader
	inClosed   bool
	isInfinite bool
	lines      []line.Line
	name       string
	mutex      sync.RWMutex
	ready      chan struct{}
	setupDone  chan struct{}
	setupOnce  sync.Once
}

type State interface {
	Keymap() *Keymap
	Query() Query
	Screen() Screen
	SetCurrentCol(int)
	CurrentCol() int
	SetCurrentLine(int)
	CurrentLine() int
	SetSingleKeyJumpMode(bool)
	SingleKeyJumpMode() bool
}

type CLIOptions struct {
	OptHelp            bool   `short:"h" long:"help" description:"show this help message and exit"`
	OptQuery           string `long:"query" description:"initial value for query"`
	OptRcfile          string `long:"rcfile" description:"path to the settings file"`
	OptVersion         bool   `long:"version" description:"print the version and exit"`
	OptBufferSize      int    `long:"buffer-size" short:"b" description:"number of lines to keep in search buffer"`
	OptEnableNullSep   bool   `long:"null" description:"expect NUL (\\0) as separator for target/output"`
	OptInitialIndex    int    `long:"initial-index" description:"position of the initial index of the selection (0 base)"`
	OptInitialMatcher  string `long:"initial-matcher" description:"specify the default matcher (deprecated)"`
	OptInitialFilter   string `long:"initial-filter" description:"specify the default filter"`
	OptPrompt          string `long:"prompt" description:"specify the prompt string"`
	OptLayout          string `long:"layout" description:"layout to be used. 'top-down' or 'bottom-up'. default is 'top-down'"`
	OptOnEmpty         string `long:"on-empty" description:"action to take when the input is finite (not a stream) and the buffer is empty. specify 'exit' to exit peco when the buffer is empty"`
	OptSelect1         bool   `long:"select-1" description:"select first item and immediately exit if the input contains only 1 item"`
	OptOnCancel        string `long:"on-cancel" description:"specify action on user cancel. 'success' or 'error'.\ndefault is 'success'. This may change in future versions"`
	OptSelectionPrefix string `long:"selection-prefix" description:"use a prefix instead of changing line color to indicate currently selected lines.\ndefault is to use colors. This option is experimental"`
	OptExec            string `long:"exec" description:"execute command instead of finishing/terminating peco.\nPlease note that this command will receive selected line(s) from stdin,\nand will be executed via '/bin/sh -c' or 'cmd /c'"`
	OptPrintQuery      bool   `long:"print-query" description:"print out the current query as first line of output"`
}

type CLI struct {
}

type RangeStart struct {
	val   int
	valid bool
}

// Buffer interface is used for containers for lines to be
// processed by peco.
type Buffer interface {
	linesInRange(int, int) []line.Line
	LineAt(int) (line.Line, error)
	Size() int
}

// MemoryBuffer is an implementation of Buffer
type MemoryBuffer struct {
	done         chan struct{}
	lines        []line.Line
	mutex        sync.RWMutex
	PeriodicFunc func()
}

type ActionMap interface {
	ExecuteAction(context.Context, *Peco, termbox.Event) error
}

type Input struct {
	actions ActionMap
	evsrc   chan termbox.Event
	mod     *time.Timer
	mutex   sync.Mutex
	state   *Peco
}

// MessageHub is the interface that must be satisfied by the
// message hub component. Unless we're in testing, github.com/peco/peco/hub.Hub
// is used.
type MessageHub interface {
	Batch(context.Context, func(context.Context), bool)
	DrawCh() chan hub.Payload
	PagingCh() chan hub.Payload
	QueryCh() chan hub.Payload
	SendDraw(context.Context, interface{})
	SendDrawPrompt(context.Context)
	SendPaging(context.Context, interface{})
	SendQuery(context.Context, string)
	SendStatusMsg(context.Context, string)
	SendStatusMsgAndClear(context.Context, string, time.Duration)
	StatusMsgCh() chan hub.Payload
}

type filterProcessor struct {
	filter filter.Filter
	query  string
}