//
//  SwiftRegex.swift
//  SwiftRegex
//
//  Created by John Holdsworth on 26/06/2014.
//  Copyright (c) 2014 John Holdsworth.
//
//  $Id: //depot/SwiftRegex/SwiftRegex.swift#37 $
//
//  This code is in the public domain from:
//  https://github.com/johnno1962/SwiftRegex
//

import Foundation

var swiftRegexCache = [String: NSRegularExpression]()

public class SwiftRegex: NSObject, BooleanType {
    
    var target: NSString
    var regex: NSRegularExpression
    
    init(target:NSString, pattern:String, options:NSRegularExpressionOptions = nil) {
        self.target = target
        if let regex = swiftRegexCache[pattern] {
            self.regex = regex
        } else {
            var error: NSError?
            if let regex = NSRegularExpression(pattern: pattern, options:options, error:&error) {
                swiftRegexCache[pattern] = regex
                self.regex = regex
            }
            else {
                SwiftRegex.failure("Error in pattern: \(pattern) - \(error)")
                self.regex = NSRegularExpression()
            }
        }
        super.init()
    }
    
    class func failure(message: String) {
        println("SwiftRegex: "+message)
        //assert(false,"SwiftRegex: failed")
    }
    
    final var targetRange: NSRange {
        return NSRange(location: 0,length: target.length)
    }
    
    final func substring(range: NSRange) -> NSString! {
        if ( range.location != NSNotFound ) {
            return target.substringWithRange(range)
        } else {
            return nil
        }
    }
    
    public func doesMatch(options: NSMatchingOptions = nil) -> Bool {
        return range(options: options).location != NSNotFound
    }
    
    public func range(options: NSMatchingOptions = nil) -> NSRange {
        return regex.rangeOfFirstMatchInString(target as! String, options: nil, range: targetRange)
    }
    
    public func match(options: NSMatchingOptions = nil) -> String! {
        return substring(range(options: options)) as! String
    }
    
    public func groups(options: NSMatchingOptions = nil) -> [String]! {
        return groupsForMatch( regex.firstMatchInString(target as! String, options: options, range: targetRange) )
    }
    
    func groupsForMatch(match: NSTextCheckingResult!) -> [String]! {
        if match != nil {
            var groups = [String]()
            for groupno in 0...regex.numberOfCaptureGroups {
                if let group = substring(match.rangeAtIndex(groupno)) as String! {
                    groups += [group]
                } else {
                    groups += ["_"] // avoids bridging problems
                }
            }
            return groups
        } else {
            return nil
        }
    }
    
    public subscript(groupno: Int) -> String! {
        get {
            return groups()[groupno]
        }
        set(newValue) {
            if let mutableTarget = target as? NSMutableString {
                for match in matchResults().reverse() {
                    let replacement = regex.replacementStringForResult( match,
                        inString: target as! String, offset: 0, template: newValue )
                    mutableTarget.replaceCharactersInRange(match.rangeAtIndex(groupno), withString: replacement)
                }
            } else {
                SwiftRegex.failure("Group modify on non-mutable")
            }
        }
    }
    
    func matchResults(options: NSMatchingOptions = nil) -> [NSTextCheckingResult] {
        return regex.matchesInString(target as! String, options: options, range: targetRange) as! [NSTextCheckingResult]
    }
    
    public func ranges(options: NSMatchingOptions = nil) -> [NSRange] {
        return matchResults(options: options).map { $0.range }
    }
    
    public func matches(options: NSMatchingOptions = nil) -> [String] {
        var returnStr = [String]()
        var t = matchResults(options: options).map { self.substring($0.range) }
        
        for str in t {
            returnStr.append(str as! String)
        }
        
        return returnStr
    }
    
    public func allGroups(options: NSMatchingOptions = nil) -> [[String]] {
        return matchResults(options: options).map { self.groupsForMatch($0) }
    }
    
    public func dictionary(options: NSMatchingOptions = nil) -> Dictionary<String,String> {
        var out = Dictionary<String,String>()
        for match in matchResults(options: options) {
            out[substring(match.rangeAtIndex(1)) as! String] =
                substring(match.rangeAtIndex(2)) as? String
        }
        return out
    }
    
    func substituteMatches(substitution: (NSTextCheckingResult, UnsafeMutablePointer<ObjCBool>) -> String,
        options:NSMatchingOptions = nil) -> NSMutableString {
            let out = NSMutableString()
            var pos = 0
            
            regex.enumerateMatchesInString(target as! String, options: options, range: targetRange ) {
                (match: NSTextCheckingResult!, flags: NSMatchingFlags, stop: UnsafeMutablePointer<ObjCBool>) in
                
                let matchRange = match.range
                out.appendString( self.substring( NSRange(location:pos, length:matchRange.location-pos) ) as! String )
                out.appendString( substitution(match, stop) )
                pos = matchRange.location + matchRange.length
            }
            
            out.appendString( substring( NSRange(location:pos, length:targetRange.length-pos) ) as! String )
            
            if let mutableTarget = target as? NSMutableString {
                var str = ""
                for char in out as String {
                    str += String(char)
                }
                
                mutableTarget.setString(str)
                return mutableTarget
            } else {
                SwiftRegex.failure("Modify on non-mutable")
                return out
            }
    }
    /* removed Beta6
    public func __conversion() -> Bool {
    return doesMatch()
    }
    
    public func __conversion() -> NSRange {
    return range()
    }
    
    public func __conversion() -> String {
    return match()
    }
    
    public func __conversion() -> [String] {
    return matches()
    }
    
    public func __conversion() -> [[String]] {
    return allGroups()
    }
    
    public func __conversion() -> [String:String] {
    return dictionary()
    }
    */
    public var boolValue: Bool {
        return doesMatch()
    }
}

extension NSString {
    public subscript(pattern: String, options: NSRegularExpressionOptions) -> SwiftRegex {
        return SwiftRegex(target: self, pattern: pattern, options: options)
    }
}

extension NSString {
    public subscript(pattern: String) -> SwiftRegex {
        return SwiftRegex(target: self, pattern: pattern)
    }
}

extension String {
    public subscript(pattern: String, options: NSRegularExpressionOptions) -> SwiftRegex {
        return SwiftRegex(target: self, pattern: pattern, options: options)
    }
}

extension String {
    public subscript(pattern: String) -> SwiftRegex {
        return SwiftRegex(target: self, pattern: pattern)
    }
}

public func RegexMutable(string: NSString) -> NSMutableString {
    return NSMutableString(string:string as! String)
}

public func ~= (left: SwiftRegex, right: String) -> NSMutableString {
    return left.substituteMatches({match, stop in
        return left.regex.replacementStringForResult( match,
            inString: left.target as! String, offset: 0, template: right )
    }, options: nil)
}

public func ~= (left: SwiftRegex, right: [String]) -> NSMutableString {
    var matchNumber = 0
    return left.substituteMatches({match, stop -> String in
        
        if ++matchNumber == right.count {
            stop.memory = true
        }
        
        return left.regex.replacementStringForResult( match,
            inString: left.target as! String, offset: 0, template: right[matchNumber-1] )
    }, options: nil)
}

public func ~= (left: SwiftRegex, right: (String) -> String) -> NSMutableString {
    // return right(left.substring(match.range))
    return left.substituteMatches(
        {match, stop -> String in
            right(left.substring(match.range) as! String)
        }, options: nil)
}

public func ~= (left: SwiftRegex, right: ([String]) -> String) -> NSMutableString {
    return left.substituteMatches({match, stop -> String in
        return right(left.groupsForMatch(match))
    }, options: nil)
}

// my take on custom threading operators from
// http://ijoshsmith.com/2014/07/05/custom-threading-operator-in-swift/

private let _queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)

public func | (left: () -> Void, right: () -> Void) {
    dispatch_async(_queue) {
        left()
        dispatch_async(dispatch_get_main_queue(), right)
    }
}

public func | <R> (left: () -> R, right: (result:R) -> Void) {
    dispatch_async(_queue) {
        let result = left()
        dispatch_async(dispatch_get_main_queue(), {
            right(result:result)
        })
    }
}

// dispatch groups { block } & { block } | { completion }
public func & (left: () -> Void, right: () -> Void) -> [() -> Void] {
    return [left, right];
}

public func & (left: [() -> Void], right: () -> Void) -> [() -> Void] {
    var out = left
    out.append( right )
    return out
}

public func | (left: [() -> Void], right: () -> Void) {
    let group = dispatch_group_create()
    
    for block in left {
        dispatch_group_async(group, _queue, block)
    }
    
    dispatch_group_notify(group, dispatch_get_main_queue(), right)
}

// parallel blocks with returns
public func & <R> (left: () -> R, right: () -> R) -> [() -> R] {
    return [left, right]
}

public func & <R> (left: [() -> R], right: () -> R) -> [() -> R] {
    var out = left
    out.append( right )
    return out
}

public func | <R> (left: [() -> R], right: (results:[R!]) -> Void) {
    let group = dispatch_group_create()
    
    var results = Array<R!>()
    for t in 0..<left.count {
        results += [nil]
    }
    
    for t in 0..<left.count {
        //dispatch_retain(group)
        dispatch_group_enter(group)
        dispatch_async(_queue, {
            results[t] = left[t]()
            dispatch_group_leave(group)
            //dispatch_release(group)
        })
    }
    
    dispatch_group_notify(group, dispatch_get_main_queue(), {
        right(results: results)
    })
}