#!/usr/bin/env io

PROG := "modpkg"

# Classes for playing with PKGDATA files.

PkgDataFieldVal := Object clone do(
	init := method(
		self stringValue := nil
		self ownerField := nil
	)
	moveTo := method(newOwner,
		ownerField remove(self)
		ownerField = newOwner
		newOwner append(self)
		self
	)
	matches := method(start,
		stringValue beginsWithSeq(start)
	)
	asString := method(stringValue)
)

PkgDataFieldValMux := Object clone do(
	init := method(
		self fieldVals := List clone
	)
	addValue := method(fv,
		fieldVals append(fv)
		self
	)
	moveTo := method(destField,
		fieldVals foreach(fv,
			fv moveTo(destField)
		)
		self
	)
	asList := method(
		fieldVals
	)
	forward := method(
		fieldVals foreach(fv, call message doInContext(fv))
	)
)

# We modify List itself so we can use the simple list() method
# to assign lists to field names in package mod scripts.
# Too magick?

List do(
	match := method(
		mux := PkgDataFieldValMux clone
		call evalArgs foreach(arg,
			foreach(fv, fv matches(arg) ifTrue(mux addValue(fv)))
		)
		mux
	)
	add := method(
		call evalArgs foreach(strVal,
			fv := PkgDataFieldVal clone
			fv stringValue = strVal asString
			fv ownerField = self
			append(fv)
		)
	)
	isEmpty := method(size == 0)
)

PkgDataFile := File clone do(
	readField := method(
		f := List clone
		(name := readLine) ifNil(return nil)
		while(strVal := readLine,
			(strVal == "") ifTrue(break)
			f add(strVal)
		)
		return list(name, f)
	)
	readFields := method(
		fields := Map clone
		while(f := readField; f isNil not, fields atPut(f at(0), f at(1)))
		fields
	)
	writeFields := method(fields,
		fields foreach(name, f,
			self write(name, "\n",
				f map(fv, (fv asString) .. "\n") join(""),
				"\n")
		)
		truncateToSize(position)
	)
)

# Classes for text files bundled into the source package. These use the PKGTREE
# directory structure for splitting sections apart and modifying them separately.

SrcPkgFileSect := Object clone do(
	init := method(
		self file := nil
		self name := nil
	)
	put := method(subSect, text,
		self file put(self name, subSect, text)
	)
)

SrcPkgFile := Object clone do(
	init := method(
		self fileName := nil
	)
	put := method(section, subSection, text,
		tree := treeDir
		sectDir := fileDir createIfAbsent directoryNamed(section) createIfAbsent
		subSectFile := sectDir fileNamed(subSection) openForAppending
		subSectFile write(text) close
	)
	treeDir := method(
		tree := Directory with("PKGTREE")
		tree exists ifFalse(
			writeln(PROG .. ": PKGTREE directory is missing.")
			System exit(1)
		)
		tree
	)
	fileDir := method(
		treeDir directoryNamed(self fileName)
	)
	exists := method(
		fileDir exists
	)
	hasSection := method(sectionName,
		fileDir directoryNamed(sectionName) exists
	)
	section := method(sectionName,
		s := SrcPkgFileSect clone
		s name = sectionName
		s file = self
		s
	)
)

# PKGBUILDs and .install files are BashFiles. We indent them and add logic for starting funcs.

BashFunc := SrcPkgFileSect clone do(
	indentLevel := 2
	init := method(
		self name := nil
	)
	indentFunc := method(text, spaceCount,
		spaces := " " repeated(spaceCount)
		spaces .. (
			text splitNoEmpties("\n") join("\n" .. spaces)
		) .. "\n"
	)
	initIfAbsent := method(
		(file hasSection(name)) ifFalse(
			put("beg", name .. "()\n{\n")
			put("end", "}\n")
		)
	)
	append := method(text,
		initIfAbsent
		put("body", indentFunc(text, indentLevel))
	)
	prepend := method(text,
		initIfAbsent
		put("beg", indentFunc(text, indentLevel))
	)
)

BashFile := SrcPkgFile clone do(
	init := method(
		self functions := List clone
	)
	func := method(name,
		f := functions detect(f, f name == name)
		f ifNil( 
			f = BashFunc clone
			functions append(f)
			f name = name
			f file = self
		)
		f
	)
)

# SourceFiles are files in the sources array that are bundled with source package.

SourceFile := Object clone do(
	init := method(
		self fileName := nil
		self fileContents := ""
	)
	append := method(seq,
		fileContents appendSeq(seq)
	)
	writeFile := method(File with(fileName) open write(fileContents) close)		
)

ModifierContext := Object clone do(
	dotInstallFuncs := list("pre_install", "post_install", "pre_upgrade", "post_upgrade")
	pbFields := list("pkgname", "pkgver", "pkgrel", "pkgdesc", "epoch",
		"url", "license", "install", "changelog", "source", "noextract",
		"md5sums", "sha512sums", "groups", "arch", "backup",
		"depends", "makedepends", "checkdepends", "optdepends",
		"conflicts", "provides", "replaces", "options",
		"packager", "maintainer")
	pbFuncs := list("build", "package", "check")

	init := method(
		self extraFields := nil

		self PKGBUILD := BashFile clone
		PKGBUILD fileName = "PKGBUILD"
		PKGBUILD sourceFiles := Map clone

		# Create shortcuts in our context for the common PKGBUILD funcs.

		pbFuncs foreach(n, self setSlot(n, PKGBUILD func(n)))

		PKGBUILD hasSourceFile := method(fileName,
			sourceFiles hasKey(fileName)
		)
		PKGBUILD sourceFile := method(fileName,
			sourceFiles hasKey(fileName) ifTrue(return sourceFiles at(fileName))
			sf := SourceFile clone
			sf fileName = fileName
			sf
		)
		PKGBUILD addPatch := method(fileName, level, text,
			hasSourceFile(fileName) ifTrue(
				writeln(PROG .. ": patch file named " .. fileName .. " already exists")
				System exit(1)
			)
			build prepend("patch -p" .. level .. " < \"$srcdir\"/" .. fileName .. "\n")
			sf := sourceFile(fileName)
			sf appendSeq(text)
			sf
		)
		PKGBUILD writeSourceFiles := method(
			sourceFiles foreach(sf, sf writeFile)
			self
		)
	)

	# Make the dotInstall slot a lazy loader for the BashFile object. Sets the .install filename
	# to match the pkgname when it is first used.
	dotInstall := lazySlot(
		name := pkgname at(0)
		name ifNil(
			writeln(PROG .. ": pkgname is missing from PKGDATA!")
			System exit(1)
		)
		newDot := BashFile clone
		newDot fileName := (name asString) .. ".install"
		newDot
	)

	# The .install function names are shortcuts into the dotInstall BashFile object.
	forward := method(
		messageName := call message name
		dotInstallFuncs contains(messageName) ifTrue(
			return dotInstall func(messageName)
		)
		resend
	)

	initFields := method(fields,
		pbFields foreach(fieldName,
			f := fields at(fieldName)
			f ifNil(f = List clone)
			self setSlot(fieldName, f)
		)

		extraFields = Map clone
		fields keys difference(pbFields) foreach(fieldName,
			extraFields atPut(fieldName, fields at(fieldName))
		)
	)

	getFields := method(
		tmp := pbFields map(fieldName,
			kv := nil
			fv := self getSlot(fieldName)
			fv isEmpty ifFalse(kv = list(fieldName, fv))
			kv
		) select(v, v) asMap merge(extraFields)
	)

	finish := method(
		PKGBUILD writeSourceFiles
		PKGBUILD sourceFiles foreach(fileName, sourceFile,
			source add(fileName)
		)
	)
)

# Startup sanity checks.

((System args size) == 2) ifFalse(
	writeln("usage: " .. PROG .. " [modifier script filename]")
	System exit(2)
)

scriptName := System args at(1)
(File exists(scriptName)) ifFalse(
	writeln(PROG .. ": script file does not exist: " .. scriptName)
	System exit(2)
)

(File exists("PKGDATA")) ifFalse(
	writeln(PROG .. ": PKGDATA file does not exist")
	System exit(2)
)

(Directory exists("PKGTREE")) ifFalse(
	writeln(PROG .. ": PKGTREE directory does not exist")
	System exit(2)
)

# Get down ta biness.

dataFile := PkgDataFile with("PKGDATA") openForUpdating

ctx := ModifierContext clone
ctx initFields(dataFile readFields)
ctx doFile(scriptName)
ctx finish

dataFile rewind
dataFile writeFields(ctx getFields)
dataFile close