--------------------------------------------------------------------------------
-- Title:               WikiContentFileService.lua
-- Description:         Like a square peg in a round hole
-- Author:              Raphaël Szwarc http://alt.textdrive.com/lua/
-- Creation Date:       January 30, 2007
-- Legal:               Copyright (C) 2007 Raphaël Szwarc
--                      Under the terms of the MIT License
--                      http://www.opensource.org/licenses/mit-license.html
--------------------------------------------------------------------------------

-- import dependencies
local HTTP = require( 'HTTP' )

local os = require( 'os' )

local getmetatable = getmetatable
local require = require
local setmetatable = setmetatable
local tostring = tostring

--------------------------------------------------------------------------------
-- WikiContentFileService
--------------------------------------------------------------------------------

module( 'WikiContentFileService' )
_VERSION = '1.0'

local self = setmetatable( _M, {} )
local meta = getmetatable( self )

--------------------------------------------------------------------------------
-- Utilities
--------------------------------------------------------------------------------

local function ValidContent( aContent, aName )
    if aContent 
    and aContent.exists 
    and ( '%s.txt' ):format( aContent.data.title ):lower() == aName:lower() then
        return true
    end
end

local function FindFile( aContent, aName ) 
    aName = aName:lower()
   
    for aFile in aContent.file do
        if aFile.name == aName then
            return aFile
        end
    end
end

local function ValidFile( aContent, aName )
    local aName = aName:lower();
    local aReference = ( '%s/file/%s' ):format( aContent.name, aName )
    local aFile = FindFile( aContent, aName )

    if not aFile then
        return false
    end
    
    if not aContent.text:find( aReference, 1, true ) then
        local aTime = os.time()
        local anInterval = aTime - aFile.modification

        if anInterval < 3600 then
            return true
        else
            aFile.delete = true
            return false
        end
    end
    
    return true
end

local function DAVContentResource( aContent )
    local aName = ( '%s.txt' ):format( aContent.data.title )
    local aCreation = aContent.creation
    local aModification = aContent.modification
    local aSize = aContent.text:len()
    local aResource = { mode = 'file', creation = aCreation, modification = aModification, name = aName, size = aSize }
    
    return aResource
end

local function DAVFileResource( aContent, aName )
    local aFile = FindFile( aContent, aName )
    local aResource = { mode = aFile.mode, modification = aFile.modification, name = aFile.name, size = aFile.size }

    return aResource    
end

local function DAVListIterator( aContent )
    local anIterator = aContent.file
    
    return function()
        local aFile = anIterator()
        
        if aFile then
            local aResource = { mode = aFile.mode, modification = aFile.modification, name = aFile.name, size = aFile.size }
            
            return aResource
        end
    end
end

local function DAVListResource( aContent )
    local anIterator = DAVListIterator( aContent )
    local aModification = aContent.modification
    local aResource = { iterator = anIterator, mode = 'directory', modification = aModification, size = 0 }
    
    return aResource
end

local function DAVResource( aContent, aName )
    if not aName then
        return DAVListResource( aContent )
    elseif ValidContent( aContent, aName ) then
        return DAVContentResource( aContent )
    elseif ValidFile( aContent, aName ) then
        return DAVFileResource( aContent, aName )
    end
end

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-- Service methods
--------------------------------------------------------------------------------

function self:get()
    local aContent = self.content
    local aName = self.name

    if aContent and aContent.exists and aName then    
        local aName = aName:lower()
        
        if ValidContent( aContent, aName ) then
            HTTP.response.header[ 'content-type' ] = 'text/plain; charset=utf-8'
        
            return aContent.text
        elseif ValidFile( aContent, aName ) then
            local File = require( 'File' )
            local HTTPFile = require( 'HTTPFile' )
            local aDirectory = File( aContent.directory.path, 'file', '' )
            local aHandler = HTTPFile( aDirectory.path )
            
            return aHandler( aName )
        end
    end
end

--------------------------------------------------------------------------------
-- DAV service methods
--------------------------------------------------------------------------------

function self:options()
    HTTP.response.header[ 'allow' ] = 'DELETE, GET, HEAD, LOCK, MOVE, OPTIONS, PROPFIND, PUT, UNLOCK'
    HTTP.response.header[ 'content-type' ] = 'text/plain'
    
    return HTTP.response.header[ 'allow' ]
end

function self:propfind()
    local aContent = self.content
    
    if aContent and aContent.exists then
        local WikiDAV = require( 'WikiDAV' )
        local aResource = DAVResource( aContent, self.name )
    
        if aResource then
            return WikiDAV( aResource ):propfind()
        end
    end
end

--------------------------------------------------------------------------------
-- Metamethods
--------------------------------------------------------------------------------

function meta:__call( aContent, aName )
    local aService = { content = aContent, name = aName }
    
    setmetatable( aService, self )
    
    return aService
end

function meta:__concat( aValue )
    return tostring( self ) .. tostring( aValue )
end

function meta:__tostring()
    return ( '%s/%s' ):format( self._NAME, self._VERSION )
end

function self:__index( aKey )
    local aValue = getmetatable( self )[ aKey ]
    
    if not aValue and aKey:find( '^get.+' ) then
        local aName = aKey:match( '^get(.+)$' )
        
        self.name = aName
        
        return function( self, anExtension )

            self.name = ( '%s.%s' ):format( aName, anExtension or '' )

            return self
        end
    elseif not aValue and aKey:find( '^propfind.+' ) then
        local aName = aKey:match( '^propfind(.+)$' )
        
        self.name = aName

        return function( self, anExtension )
            
            self.name = ( '%s.%s' ):format( aName, anExtension or '' )

            return self
        end
    end
    
    self[ aKey ] = aValue
    
    return aValue
end

function self:__concat( aValue )
    return tostring( self ) .. tostring( aValue )
end

function self:__tostring()
    return tostring( self.name )
end