From 78a19485453357231327cc759f0f5e3c3f0e838c Mon Sep 17 00:00:00 2001
From: Marty Oehme <marty.oehme@gmail.com>
Date: Fri, 30 Oct 2020 18:44:50 +0100
Subject: [PATCH] Add link formatting function

Function takes an anchor (and optional link text and formatting style)
and transforms the input into a link to an anchor id.

Currently works for markdown and wikilink style link transforms.
---
 lua/zettelkasten/link.lua         | 17 +++++++++++++++++
 lua/zettelkasten/link_spec.lua    | 17 +++++++++++++++++
 lua/zettelkasten/options.lua      |  7 +++++++
 lua/zettelkasten/options_spec.lua | 15 +++++++++++++++
 4 files changed, 56 insertions(+)

diff --git a/lua/zettelkasten/link.lua b/lua/zettelkasten/link.lua
index b7ae5f9..d78886e 100644
--- a/lua/zettelkasten/link.lua
+++ b/lua/zettelkasten/link.lua
@@ -51,4 +51,21 @@ function L.style_wiki(link, text)
     return "[[" .. link .. pipe .. "]]"
 end
 
+-- Returns the correctly formatted link to a zettel with the anchor passed in.
+-- Takes an optional link text which will be added to the link.
+-- Takes an optional style according to which the link will be transformed.
+function L.create(anchor, text, style)
+    local link = L.clean(text)
+    style = style or o.zettel().link_style
+
+    if style == "markdown" then
+        link = L.append_extension(L.prepend_anchor(anchor, link))
+        return L.style_markdown(link, text)
+
+    elseif style == "wiki" then
+        return L.style_wiki(anchor, text)
+    end
+    error("Link creation failed.")
+end
+
 return L
diff --git a/lua/zettelkasten/link_spec.lua b/lua/zettelkasten/link_spec.lua
index 66a26e3..58bab50 100644
--- a/lua/zettelkasten/link_spec.lua
+++ b/lua/zettelkasten/link_spec.lua
@@ -89,3 +89,20 @@ describe("style_wiki", function()
                     link.style_wiki("1910291645", "  hi     "))
     end)
 end)
+
+describe("create_link", function()
+    it("should create a working link using set options in vim", function()
+        vim.g.zettel_extension = ".md"
+        vim.g.zettel_anchor_separator = "_"
+        vim.g.zettel_link_style = "markdown"
+        assert.same("[My FILE NAME](1910291645_my-file-name.md)",
+                    link.create("1910291645", "My FILE NAME"))
+    end)
+    it("should create a working link if style is manually set", function()
+        vim.g.zettel_extension = ".md"
+        vim.g.zettel_anchor_separator = "_"
+        vim.g.zettel_link_style = "markdown"
+        assert.same("[[1910291645|My FILE NAME]]",
+                    link.create("1910291645", "My FILE NAME", "wiki"))
+    end)
+end)
diff --git a/lua/zettelkasten/options.lua b/lua/zettelkasten/options.lua
index f748d74..f47d9a8 100644
--- a/lua/zettelkasten/options.lua
+++ b/lua/zettelkasten/options.lua
@@ -2,6 +2,7 @@ local Opt = {}
 
 -- setting defaults
 local ZETTEL_EXTENSION = ".md"
+local ZETTEL_LINK_STYLE = "markdown"
 local ANCHOR_SEPARATOR = "_"
 -- TODO zettel_root = vim.g["zettel_root"] or vim.b["zettel_root"] or "~/documents/notes",
 -- TODO zettel_anchor_pattern = regex? -> needs custom creation function in `create_anchor`
@@ -11,6 +12,12 @@ function Opt.zettel()
     options.extension =
         vim.g["zettel_extension"] or vim.b["zettel_extension"] or
             ZETTEL_EXTENSION
+    options.link_style = vim.g["zettel_link_style"] or
+                             vim.b["zettel_link_style"] or ZETTEL_LINK_STYLE
+
+    if options.link_style ~= "wiki" and options.link_style ~= "markdown" then
+        error("zettel_link_style can only be set to markdown or wiki.")
+    end
     return options
 end
 
diff --git a/lua/zettelkasten/options_spec.lua b/lua/zettelkasten/options_spec.lua
index 0ea22bd..f1dda71 100644
--- a/lua/zettelkasten/options_spec.lua
+++ b/lua/zettelkasten/options_spec.lua
@@ -28,4 +28,19 @@ describe("zettel options", function()
     end)
     it("should return the default anchor separator if not set in vim",
        function() assert.same("_", opt.anchor().separator) end)
+
+    it("should return the global link style if set in vim", function()
+        _G.vim.g.zettel_link_style = "wiki"
+        assert.same("wiki", opt.zettel().link_style)
+    end)
+    it("should return the buffer link style if set in vim", function()
+        _G.vim.b.zettel_link_style = "wiki"
+        assert.same("wiki", opt.zettel().link_style)
+    end)
+    it("should return the default link style if not set in vim",
+       function() assert.same("markdown", opt.zettel().link_style) end)
+    it("should error on entries other than markdown/wiki", function()
+        _G.vim.g.zettel_link_style = "idontbelong"
+        assert.is_error(function() opt.zettel() end)
+    end)
 end)