-- take str, delete all chars between
-- indices i0 and i1 (inclusive), and
-- insert newstr into that space
local function splice(str,i0,i1, newstr)
	return sub(str,1,max(1,i0)-1)..(newstr or "")..sub(str,i1+1)
end

-- use str:find to do sed-like file editing.
-- no lua patterns, just literal string matching
-- return str, but replace the first instance of cut with paste
local function _replace(str,cut,paste)
	local i0,i1 = str:find(cut,1,true) -- no pattern-matching
	if not i0 then
		return str,false
	end
	return splice(str,i0,i1,paste),true
end

local function sedish(fname,mods)
	local src = fetch(fname)
	if not src then
		printh("sedish: couldn't find file "..fname)
		return
	end

	for i,mod in ipairs(mods) do
		local cut,paste = unpack(mod)
		-- printh(cut.." "..paste)
		if not cut or not paste then
			printh("sedish: bad cut/paste data in "..fname)
			return
		end
		local changed
		src,changed = _replace(src,cut,paste)
		if not changed then
			printh("sedish: mod #"..i.." did nothing to "..fname)
		end
		if not src or #src==0 then
			printh("sedish: bad result in "..fname)
			return
		end
	end
	-- printh("storing "..fname..": "..sub(src,1,100):gsub("[\n\r]",""))
	store(fname,src)
end

sedish("/system/lib/gui_ed.lua",{
	{ -- fix alt-tab annoyance (pressing alt-tab inserts tab character into code)
		[[if (keyp("tab")) then]],
		[[if keyp"tab" and not key"alt" then]],
	},
})

sedish("/system/apps/podtree.p64/main.lua",{
	{ -- fix podtree bug (pressing enter crashes the program)
		[[if(key("shift")) return true]],
		[[if(_ENV.key("shift")) return true]],
	},
})

-- (you need to open a new gfx tab for these gfx.p64 edits to work)
sedish("/system/apps/gfx.p64/pal.lua",{
	{ -- show pal numbers
		[[pcols[x + y*epr])]],
		[[pcols[x + y*epr])if pal_swatch==1 and x%2==0 then print(pcols[x + y*epr],x*ww+5,y*ww+1,0) end]],
	},
})
-- sedish("/system/apps/gfx.p64/nav.lua",{
-- 	{ -- display sprite numbers in hex
-- 		[[string.format("%03d",current_item)]],
-- 		[[string.format("x%02x",current_item)]],
-- 	},
-- })
sedish("/system/apps/gfx.p64/update.lua",{
	{ -- don't flip when you press ctrl-v (noticeable when undoing)
		[[if (keyp("v"))]],
		[[if (keyp"v" and not key"ctrl")]],
	},
})

sedish("/system/lib/gui_ed.lua",{
	{ -- fix custom key callbacks in gui
		[[content.key_callback(k)]],
		[[content.key_callback[k](k)]],
	},
})

-- doesn't work for startup terminal
--   need to wait for it to regenerate, e.g. after running a fullscreen app
sedish("/system/apps/terminal.lua",{
	{ -- add custom terminal_cd event (to let my z.lua util "run" cd for you)
		[[-- scroll down only if needed]],
		[[on_event("terminal_cd",function(msg) cd(msg.path) end)]],
	},
	{ -- show slightly different terminal prompt when in upgraded terminal
		[[return result -- custom prompt goes here]],
		[[return "\f6"..pwd().."\f7 > "]],
	},
})

printh "sedish done"

sedish("/system/lib/gui_ed.lua",{
	{ -- fix ctrl-shift-z acting like normal ctrl-z
		[[undo_stack:undo()]],
		[[if key"shift" then undo_stack:redo() else undo_stack:undo() end]],
	},
})

sedish("/system/apps/filenav.p64/finfo.lua", {
	{-- Mod: Enable renaming files on desktop
	[[		-- rename 
		if (mode ~= "desktop") then]],
	[[
			-- rename 
		if (true) then]] -- This is lazy, but it gets it done in the fewest amount of lines
	}
})