// Copyright (C) 2016 Mikael Berthe <mikael@lilotux.net>. All rights reserved.

// Use of this source code is governed by the MIT license,

// which can be found in the LICENSE file.

// gotak is a CLI wrapper for the takuzu package.

package main

import (

	"fmt"

	"log"

	"os"

	"time"

	"github.com/spf13/pflag"

)

var verbosity int

func newTakuzuGameBoard(size int, simple bool, jobs int, buildBoardTimeout, reduceBoardTimeout time.Duration, minRatio, maxRatio int) *takuzu.Takuzu {

	results := make(chan *takuzu.Takuzu)

	newTak := func(i int) {

		takuzu, err := takuzu.NewRandomTakuzu(size, simple, fmt.Sprintf("%v", i),

			buildBoardTimeout, reduceBoardTimeout, minRatio, maxRatio)

		if err == nil && takuzu != nil {

			results <- takuzu

			if verbosity > 0 && jobs > 1 {

				log.Printf("Worker #%d done.", i)

			}

		} else {

			results <- nil

		}

	}

	if jobs == 0 {

		return nil

	}

	for i := 0; i < jobs; i++ {

		go newTak(i)

	}

	tak := <-results

	return tak

}

func main() {

	vbl := pflag.Uint("vl", 0, "Verbosity Level")

	simple := pflag.Bool("simple", false, "Only look for trivial solutions")

	out := pflag.Bool("out", false, "Send solution string to output")

	board := pflag.String("board", "", "Load board string")

	schrodLvl := pflag.Uint("x-sl", 0, "[Advanced] Schrödinger level")

	resolveTimeout := pflag.Duration("x-timeout", 0, "[Advanced] Resolution timeout")

	buildBoardTimeout := pflag.Duration("x-build-timeout", 5*time.Minute, "[Advanced] Build timeout per resolution")

	reduceBoardTimeout := pflag.Duration("x-reduce-timeout", 20*time.Minute, "[Advanced] Reduction timeout")

	buildMinRatio := pflag.Uint("x-new-min-ratio", 55, "[Advanced] Build empty cell ratio (40-60)")

	buildMaxRatio := pflag.Uint("x-new-max-ratio", 62, "[Advanced] Build empty cell ratio (50-99)")

	all := pflag.Bool("all", false, "Look for all possible solutions")

	reduce := pflag.Bool("reduce", false, "Try to reduce the number of digits")

	buildNewSize := pflag.Uint("new", 0, "Build a new takuzu board (with given size)")

	pdfFileName := pflag.String("to-pdf", "", "PDF output file name")

	workers := pflag.Uint("workers", 1, "Number of parallel workers (use with --new)")

	pflag.Parse()

	verbosity = int(*vbl)

	takuzu.SetVerbosityLevel(verbosity)

	takuzu.SetSchrodingerLevel(*schrodLvl)

	var tak *takuzu.Takuzu

	if *board != "" {

		var err error

		tak, err = takuzu.NewFromString(*board)

		if tak == nil || err != nil {

			fmt.Fprintln(os.Stderr, "Error:", err)

			tak = nil

		}

	}

	if *buildNewSize > 0 {

		if verbosity > 1 {

			log.Printf("buildBoardTimeout:   %v", *buildBoardTimeout)

			log.Printf("reduceBoardTimeout:  %v", *reduceBoardTimeout)

			log.Printf("Free cell min ratio: %v", *buildMinRatio)

			log.Printf("Free cell max ratio: %v", *buildMaxRatio)

		}

		tak = newTakuzuGameBoard(int(*buildNewSize), *simple,

			int(*workers),

			*buildBoardTimeout, *reduceBoardTimeout,

			int(*buildMinRatio), int(*buildMaxRatio))

	}

	if tak == nil {

		fmt.Fprintln(os.Stderr, "Could not create takuzu board.")

		os.Exit(255)

	}

	tak.DumpBoard()

	fmt.Println()

	if *pdfFileName != "" {

		if err := tak2pdf(tak, *pdfFileName); err != nil {

			log.Println(err)

			os.Exit(1)

		}

		if *out {

			tak.DumpString()

		}

		os.Exit(0)

	}

	if *buildNewSize > 0 {

		if *out {

			tak.DumpString()

		}

		os.Exit(0)

	}

	if *reduce {

		if verbosity > 1 {

			log.Printf("buildBoardTimeout:   %v", *buildBoardTimeout)

			log.Printf("reduceBoardTimeout:  %v", *reduceBoardTimeout)

		}

		var err error

		if tak, err = tak.ReduceBoard(*simple, "0", *buildBoardTimeout, *reduceBoardTimeout); err != nil {

			log.Println(err)

			os.Exit(1)

		}

		tak.DumpBoard()

		fmt.Println()

		if *out {

			tak.DumpString()

		}

		os.Exit(0)

	}

	if *simple {

		full, err := tak.TrySolveTrivial()

		if err != nil {

			log.Println(err)

			os.Exit(1)

		}

		if !full {

			tak.DumpBoard()

			fmt.Println()

			if *out {

				tak.DumpString()

			}

			log.Println("The takuzu could not be completed using trivial methods.")

			os.Exit(2)

		}

		log.Println("The takuzu is correct and complete.")

		tak.DumpBoard()

		fmt.Println()

		if *out {

			tak.DumpString()

		}

		os.Exit(0)

	}

	var allSol *[]takuzu.Takuzu

	if *all {

		allSol = &[]takuzu.Takuzu{}

	}

	res, err := tak.TrySolveRecurse(allSol, *resolveTimeout)

	if err != nil && verbosity > 1 {

		// The last trivial resolution failed

		log.Println("Trivial resolution failed:", err)

	}

	// Ignoring res & err if a full search was requested

	if *all {

		log.Println(len(*allSol), "solution(s) found.")

		if len(*allSol) > 0 {

			for _, s := range *allSol {

				if *out {

					s.DumpString()

				} else {

					s.DumpBoard()

					fmt.Println()

				}

			}

			if len(*allSol) > 1 {

				os.Exit(3)

			}

			os.Exit(0)

		}

		fmt.Println("No solution found.")

		os.Exit(2)

	}

	if err != nil {

		log.Println(err)

		os.Exit(1)

	}

	if res != nil {

		res.DumpBoard()

		fmt.Println()

		if *out {

			res.DumpString()

		}

		os.Exit(0)

	}

	fmt.Println("No solution found.")

	os.Exit(2)

}