package slinguist

import (
	"path/filepath"
	"strings"

	"gopkg.in/toqueteos/substring.v1"
)

func GetLanguageByContent(filename string, content []byte) (lang string, safe bool) {
	ext := strings.ToLower(filepath.Ext(filename))
	if fnMatcher, ok := matchers[ext]; ok {
		lang, safe = fnMatcher(content)
		return
	}

	return GetLanguageByExtension(filename)
}

type languageMatcher func([]byte) (string, bool)

var matchers = map[string]languageMatcher{
	".bf": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`(fprintf|function|return)`).Match(i) {
			return "HyPhy", true
		}

		return "Brainfuck", false
	},
	".b": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`(include|modules)`).Match(i) {
			return "Limbo", true
		}

		return "Brainfuck", false
	},
	".bb": func(i []byte) (string, bool) {
		if blitzBasicMatcher.Match(i) {
			return "BlitzBasic", true
		} else if substring.BytesRegexp(`^\s*(# |include|require)\b`).Match(i) {
			return "BitBake", true
		}

		return OtherLanguage, false
	},
	".cl": func(i []byte) (string, bool) {
		if commonLispMatcher.Match(i) {
			return "Common Lisp", true
		} else if coolMatcher.Match(i) {
			return "Cool", true
		} else if openCLMatcher.Match(i) {
			return "OpenCL", true
		}

		return OtherLanguage, false
	},
	".cls": func(i []byte) (string, bool) {
		if apexMatcher.Match(i) {
			return "Apex", true
		} else if openEdgeABLMatcher.Match(i) {
			return "OpenEdge ABL", true
		} else if texMatcher.Match(i) {
			return "TeX", true
		} else if visualBasicMatcher.Match(i) {
			return "Visual Basic", true

		}

		return OtherLanguage, false
	},
	".cs": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`![\w\s]+methodsFor: `).Match(i) {
			return "Smalltalk", true
		}

		return "C#", true
	},
	".ch": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`(?i)^\s*#\s*(if|ifdef|ifndef|define|command|xcommand|translate|xtranslate|include|pragma|undef)\b`).Match(i) {
			return "xBase", true
		}

		return "Charity", true
	},
	".d": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`^module `).Match(i) {
			return "D", true
		} else if substring.BytesRegexp(`((dtrace:::)?BEGIN|provider |#pragma (D (option|attributes)|ident)\s)`).Match(i) {
			return "DTrace", true
		} else if substring.BytesRegexp(`(\/.*:( .* \\)$| : \\$|^ : |: \\$)`).Match(i) {
			return "Makefile", true
		}

		return OtherLanguage, true
	},
	".ecl": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`^[^#]+:-`).Match(i) {
			return "ECLiPSe", true
		} else if substring.BytesHas(`:=`).Match(i) {
			return "ECL", true
		}

		return OtherLanguage, true
	},
	".es": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`\s*(?:%%|main\s*\(.*?\)\s*->)`).Match(i) {
			return "Erlang", true
		} else if substring.BytesRegexp(`(?:\/\/|("|')use strict\\1|export\s+default\s|\/\*.*?\*\/)`).Match(i) {
			return "JavaScript", true
		}

		return OtherLanguage, true
	},
	".f": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`\n: `).Match(i) {
			return "Forth", true
		} else if substring.BytesRegexp(`(?i)^([c*][^abd-z]|      (subroutine|program|end)\s|\s*!)`).Match(i) {
			return "FORTRAN", true
		}

		return OtherLanguage, false
	},
	".fr": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`^(: |also |new-device|previous )`).Match(i) {
			return "Forth", true
		} else if substring.BytesRegexp(`\s*(import|module|package|data|type)`).Match(i) {
			return "Frege", true
		}

		return "Text", false
	},
	".j": func(i []byte) (string, bool) {
		if objectiveCMatcher.Match(i) {
			return "Objective-J", true
		}

		return "Jasmin", false
	},
	".inc": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`^<\?(?:php)?`).Match(i) {
			return "PHP", true
		}

		return OtherLanguage, true
	},
	".m": func(i []byte) (string, bool) {
		if objectiveCMatcher.Match(i) {
			return "Objective-C", true
		} else if substring.BytesHas(`:- module`).Match(i) {
			return "Mercury", true
		} else if substring.BytesRegexp(`\n: `).Match(i) {
			return "MUF", true
		} else if substring.BytesRegexp(`\n\s*;`).Match(i) {
			return "M", true
		} else if substring.BytesRegexp(`\n\s*\(\*`).Match(i) {
			return "Mathematica", true
		} else if substring.BytesRegexp(`\n\s*%`).Match(i) {
			return "Matlab", true
		} else if substring.BytesRegexp(`\w+\s*:\s*module\s*{`).Match(i) {
			return "Limbo", true
		}

		return OtherLanguage, false
	},
	".ms": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`[.'][a-z][a-z](\s|$)`).Match(i) {
			return "Groff", true
		}

		return "MAXScript", true
	},
	".md": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`\n[-a-z0-9=#!\*\[|]`).Match(i) {
			return "Markdown", true
		} else if substring.BytesRegexp(`\n(;;|\(define_)`).Match(i) {
			return "GCC Machine Description", true
		}

		return OtherLanguage, false
	},
	".moo": func(i []byte) (string, bool) {
		if substring.BytesHas(`:- module`).Match(i) {
			return "Mercury", true
		}

		return "Moocode", false
	},
	".e": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`feature\s--`).Match(i) {
			return "Eiffel", true
		}

		return "E", false
	},
	".fs": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`\n(: |new-device)`).Match(i) {
			return "Forth", true
		} else if substring.BytesRegexp(`\s*(#light|import|let|module|namespace|open|type)`).Match(i) {
			return "F#", true
		} else if substring.BytesRegexp(`(#version|precision|uniform|varying|vec[234])`).Match(i) {
			return "GLSL", true
		} else if substring.BytesRegexp(`#include|#pragma\s+(rs|version)|__attribute__`).Match(i) {
			return "Filterscript", true
		}

		return OtherLanguage, false
	},
	".gs": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`uses java\.`).Match(i) {
			return "Gosu", true
		}

		return "JavaScript", false
	},
	".h": func(i []byte) (string, bool) {
		if objectiveCMatcher.Match(i) {
			return "Objective-C", true
		} else if cPlusPlusMatcher.Match(i) {
			return "C++", true
		}

		return "C", true
	},
	".hh": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`^<\?(?:hh)?`).Match(i) {
			return "Hack", true
		} else if cPlusPlusMatcher.Match(i) {
			return "C++", true
		}

		return OtherLanguage, false
	},
	".l": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`\(def(un|macro)\s`).Match(i) {
			return "Common Lisp", true
		} else if substring.BytesRegexp(`(%[%{}]xs|<.*>)`).Match(i) {
			return "Lex", true
		} else if substring.BytesRegexp(`\.[a-z][a-z](\s|$)`).Match(i) {
			return "Groff", true
		} else if substring.BytesRegexp(`(de|class|rel|code|data|must)`).Match(i) {
			return "PicoLisp", true
		}

		return OtherLanguage, false
	},
	".ls": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`\s*package\s*[\w\.\/\*\s]*\s*{`).Match(i) {
			return "LoomScript", true
		}

		return "LiveScript", false
	},
	".n": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`^[.']`).Match(i) {
			return "Groff", true
		} else if substring.BytesRegexp(`(module|namespace|using)`).Match(i) {
			return "Nemerle", true
		}

		return OtherLanguage, false
	},
	".ncl": func(i []byte) (string, bool) {
		if substring.BytesHas("THE_TITLE").Match(i) {
			return "Text", true
		}

		return "NCL", true
	},
	".mod": func(i []byte) (string, bool) {
		if substring.BytesHas("<!ENTITY ").Match(i) {
			return "XML", true
		} else if substring.BytesRegexp(`MODULE\s\w+\s*;`).Match(i) || substring.BytesRegexp(`(?i)\s*END \w+;$`).Match(i) {
			return "Modula-2", true
		}

		return "Linux Kernel Module", true
	},
	".lisp": func(i []byte) (string, bool) {
		if commonLispMatcher.Match(i) {
			return "Common Lisp", true
		} else if substring.BytesRegexp(`\s*\(define `).Match(i) {
			return "NewLisp", true
		}

		return OtherLanguage, false
	},
	".pm": func(i []byte) (string, bool) {
		if perlMatcher.Match(i) {
			return "Perl", true
		} else if perl6Matcher.Match(i) {
			return "Perl6", true
		}

		return "Perl", false
	},
	".t": func(i []byte) (string, bool) {
		if perlMatcher.Match(i) {
			return "Perl", true
		} else if perl6Matcher.Match(i) {
			return "Perl6", true
		} else if substring.BytesRegexp(`^\s*%|^\s*var\s+\w+\s*:\s*\w+`).Match(i) {
			return "Turing", true
		} else if substring.BytesRegexp(`^\s*use\s+v6\s*;`).Match(i) {
			return "Perl6", true
		} else if substring.BytesRegexp(`terra\s`).Match(i) {
			return "Terra", true
		}

		return "Perl", false
	},
	".ts": func(i []byte) (string, bool) {
		if substring.BytesHas("</TS>").Match(i) {
			return "XML", true
		}

		return "TypeScript", true
	},
	".tsx": func(i []byte) (string, bool) {
		if substring.BytesHas("</tileset>").Match(i) {
			return "XML", true
		}

		return "TypeScript", true
	},
	".tst": func(i []byte) (string, bool) {
		if substring.BytesHas("gap> ").Match(i) {
			return "GAP", true
		}

		return "Scilab", true
	},
	".r": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`(?i)\bRebol\b`).Match(i) {
			return "Rebol", true
		} else if substring.BytesHas("<-").Match(i) {
			return "R", true
		}

		return OtherLanguage, false
	},
	".rs": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`\n(use |fn |mod |pub |macro_rules|impl|#!?\[)`).Match(i) {
			return "Rust", true
		} else if substring.BytesRegexp(`#include|#pragma\s+(rs|version)|__attribute__`).Match(i) {
			return "RenderScript", true
		}

		return OtherLanguage, false
	},
	".rpy": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`(import|from|class|def)\s`).Match(i) {
			return "Python", true
		}

		return "Ren'Py", false
	},
	".v": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`\nendmodule`).Match(i) {
			return "Verilog", true
		} else if substring.BytesRegexp(`(Require|Import)`).Match(i) {
			return "Coq", true
		}

		return OtherLanguage, false
	},
	".pl": func(i []byte) (string, bool) {
		if prologMatcher.Match(i) {
			return "Prolog", true
		} else if perl6Matcher.Match(i) {
			return "Perl6", true
		}

		return "Perl", false
	},
	".pro": func(i []byte) (string, bool) {
		if prologMatcher.Match(i) {
			return "Prolog", true
		}

		return OtherLanguage, false
	},
	".pod": func(i []byte) (string, bool) {
		if substring.BytesRegexp(`=\w+\n`).Match(i) {
			return "Pod", true
		}

		return "Perl", false
	},
	".toc": func(i []byte) (string, bool) {
		if substring.BytesRegexp("## |@no-lib-strip@").Match(i) {
			return "World of Warcraft Addon Data", true
		} else if substring.BytesRegexp("(contentsline|defcounter|beamer|boolfalse)").Match(i) {
			return "TeX", true
		}

		return OtherLanguage, false
	},
	".sls": func(i []byte) (string, bool) {
		if substring.BytesRegexp("## |@no-lib-strip@").Match(i) {
			return "World of Warcraft Addon Data", true
		} else if substring.BytesRegexp("(contentsline|defcounter|beamer|boolfalse)").Match(i) {
			return "TeX", true
		}

		return OtherLanguage, false
	},
	".sql": func(i []byte) (string, bool) {
		if pgSQLMatcher.Match(i) {
			return "PLpgSQL", true
		} else if db2SQLMatcher.Match(i) {
			return "SQLPL", true
		} else if oracleSQLMatcher.Match(i) {
			return "PLSQL", true
		}

		return "SQL", false
	},
}

func init() {
	matchers[".for"] = matchers[".f"]
	matchers[".lsp"] = matchers[".lisp"]
}

var (
	blitzBasicMatcher = substring.BytesOr(
		substring.BytesHas(`End Function`),
		substring.BytesRegexp(`\\s*;`),
	)
	cPlusPlusMatcher = substring.BytesOr(
		substring.BytesRegexp(`\s*template\s*<`),
		substring.BytesRegexp(`\s*#\s*include <(cstdint|string|vector|map|list|array|bitset|queue|stack|forward_list|unordered_map|unordered_set|(i|o|io)stream)>`),
		substring.BytesRegexp(`\n[ \t]*try`),
		substring.BytesRegexp(`\n[ \t]*(class|(using[ \t]+)?namespace)\s+\w+`),
		substring.BytesRegexp(`\n[ \t]*(private|public|protected):\n`),
		substring.BytesRegexp(`std::\w+`),
		substring.BytesRegexp(`[ \t]*catch\s*`),
	)
	commonLispMatcher = substring.BytesRegexp("(?i)(defpackage|defun|in-package)")
	coolMatcher       = substring.BytesRegexp("(?i)class")
	openCLMatcher     = substring.BytesOr(
		substring.BytesHas("\n}"),
		substring.BytesHas("}\n"),
		substring.BytesHas(`/*`),
		substring.BytesHas(`//`),
	)
	apexMatcher = substring.BytesOr(
		substring.BytesHas("{\n"),
		substring.BytesHas("}\n"),
	)
	texMatcher = substring.BytesOr(
		substring.BytesHas(`%`),
		substring.BytesHas(`\`),
	)
	openEdgeABLMatcher = substring.BytesRegexp(`(?i)(class|define|interface|method|using)\b`)
	visualBasicMatcher = substring.BytesOr(
		substring.BytesHas("'*"),
		substring.BytesRegexp(`(?i)(attribute|option|sub|private|protected|public|friend)\b`),
	)
	mathematicaMatcher = substring.BytesHas(`^\s*\(\*`)
	matlabMatcher      = substring.BytesRegexp(`\b(function\s*[\[a-zA-Z]+|pcolor|classdef|figure|end|elseif)\b`)
	objectiveCMatcher  = substring.BytesRegexp(
		`@(interface|class|protocol|property|end|synchronised|selector|implementation)\b|#import\s+.+\.h[">]`)

	prologMatcher = substring.BytesRegexp(`^[^#]+:-`)
	perlMatcher   = substring.BytesRegexp(`use strict|use\s+v?5\.`)
	perl6Matcher  = substring.BytesRegexp(`(use v6|(my )?class|module)`)
	pgSQLMatcher  = substring.BytesOr(
		substring.BytesRegexp(`(?i)\\i\b|AS \$\$|LANGUAGE '?plpgsql'?`),
		substring.BytesRegexp(`(?i)SECURITY (DEFINER|INVOKER)`),
		substring.BytesRegexp(`BEGIN( WORK| TRANSACTION)?;`),
	)
	db2SQLMatcher = substring.BytesOr(
		substring.BytesRegexp(`(?i)(alter module)|(language sql)|(begin( NOT)+ atomic)`),
		substring.BytesRegexp(`(?i)signal SQLSTATE '[0-9]+'`),
	)
	oracleSQLMatcher = substring.BytesOr(
		substring.BytesRegexp(`(?i)\$\$PLSQL_|XMLTYPE|sysdate|systimestamp|\.nextval|connect by|AUTHID (DEFINER|CURRENT_USER)`),
		substring.BytesRegexp(`(?i)constructor\W+function`),
	)
)