//  Copyright (c) 2014 Couchbase, 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 ansi

import (
	"github.com/blevesearch/bleve/registry"
	"github.com/blevesearch/bleve/search/highlight"
)

const Name = "ansi"

const DefaultAnsiHighlight = BgYellow

type FragmentFormatter struct {
	color string
}

func NewFragmentFormatter(color string) *FragmentFormatter {
	return &FragmentFormatter{
		color: color,
	}
}

func (a *FragmentFormatter) Format(f *highlight.Fragment, orderedTermLocations highlight.TermLocations) string {
	rv := ""
	curr := f.Start
	for _, termLocation := range orderedTermLocations {
		if termLocation == nil {
			continue
		}
		// make sure the array positions match
		if !highlight.SameArrayPositions(f.ArrayPositions, termLocation.ArrayPositions) {
			continue
		}
		if termLocation.Start < curr {
			continue
		}
		if termLocation.End > f.End {
			break
		}
		// add the stuff before this location
		rv += string(f.Orig[curr:termLocation.Start])
		// add the color
		rv += a.color
		// add the term itself
		rv += string(f.Orig[termLocation.Start:termLocation.End])
		// reset the color
		rv += Reset
		// update current
		curr = termLocation.End
	}
	// add any remaining text after the last token
	rv += string(f.Orig[curr:f.End])

	return rv
}

// ANSI color control escape sequences.
// Shamelessly copied from https://github.com/sqp/godock/blob/master/libs/log/colors.go
const (
	Reset      = "\x1b[0m"
	Bright     = "\x1b[1m"
	Dim        = "\x1b[2m"
	Underscore = "\x1b[4m"
	Blink      = "\x1b[5m"
	Reverse    = "\x1b[7m"
	Hidden     = "\x1b[8m"
	FgBlack    = "\x1b[30m"
	FgRed      = "\x1b[31m"
	FgGreen    = "\x1b[32m"
	FgYellow   = "\x1b[33m"
	FgBlue     = "\x1b[34m"
	FgMagenta  = "\x1b[35m"
	FgCyan     = "\x1b[36m"
	FgWhite    = "\x1b[37m"
	BgBlack    = "\x1b[40m"
	BgRed      = "\x1b[41m"
	BgGreen    = "\x1b[42m"
	BgYellow   = "\x1b[43m"
	BgBlue     = "\x1b[44m"
	BgMagenta  = "\x1b[45m"
	BgCyan     = "\x1b[46m"
	BgWhite    = "\x1b[47m"
)

func Constructor(config map[string]interface{}, cache *registry.Cache) (highlight.FragmentFormatter, error) {
	color := DefaultAnsiHighlight
	colorVal, ok := config["color"].(string)
	if ok {
		color = colorVal
	}
	return NewFragmentFormatter(color), nil
}

func init() {
	registry.RegisterFragmentFormatter(Name, Constructor)
}