feat(policy): add 'by filetype' policy (#72)

Author: linrongbin16

README.md

@@ -59,10 +59,9 @@ It allow you play them with multiple playback settings (policies):
 And multiple trigger timings (colorschemes don't have end time):
 
 - On startup.
-- Fixed interval (todo).
+- Fixed interval.
 - Date time (todo).
-- By filetype (todo).
-- Manual (todo).
+- By filetype.
 
 ## 📖 Table of contents
 
@@ -182,7 +181,7 @@ require('colorbox').setup({
     --- @alias colorbox.BuiltinPolicyConfig "shuffle"|"in_order"|"reverse_order"|"single"
     ---
     -- by filetype policy: buffer filetype => color name
-    --- @alias colorbox.ByFileTypePolicyConfig {implement:colorbox.BuiltinPolicyConfig|table<string, string>}
+    --- @alias colorbox.ByFileTypePolicyConfig {mapping:table<string, string>,fallback:string}
     ---
     -- fixed interval seconds
     --- @alias colorbox.FixedIntervalPolicyConfig {seconds:integer,implement:colorbox.BuiltinPolicyConfig}
@@ -191,7 +190,7 @@ require('colorbox').setup({
     --- @type colorbox.PolicyConfig
     policy = "shuffle",
 
-    --- @type "startup"|"interval"|"filetype"
+    --- @type "startup"|"interval"|"bufferchanged"
     timing = "startup",
 
     -- (Optional) filters that disable some colors that you don't want.
@@ -264,11 +263,11 @@ require('colorbox').setup({
 
 Timing and policy configs have to work together.
 
-- `timing`: 'startup' (on nvim start), 'interval' (fixed interval seconds), 'filetype' (by buffer filetype, todo).
+- `timing`: 'startup', 'interval', 'bufferchanged'.
 - `policy`:
-  - Builtin policies (see `colorbox.BuiltinPolicyConfig`): 'shuffle' (random select), 'in_order' ('A-Z' color names), 'reverse_order' ('Z-A' color names), 'single' (don't change).
-  - Fixed interval policies (see `colorbox.ByFileTypePolicyConfig`): todo.
-  - By buffer filetype policies (see ``)
+  - Builtin policies (see `colorbox.BuiltinPolicyConfig`): working with 'startup' timing.
+  - Fixed interval policies (see `colorbox.FixedIntervalPolicyConfig`): working with 'interval' timing.
+  - By filetype policies (see `colorbox.ByFileTypePolicyConfig`): working with 'bufferchanged' timing.
 
 To choose a fixed colorscheme on nvim start, please use:
 
@@ -289,6 +288,23 @@ require('colorbox').setup({
 })
 ```
 
+To choose a colorscheme by file type, please use:
+
+```lua
+require('colorbox').setup({
+    policy = {
+        mapping = {
+            lua = "PaperColor",
+            yaml = "everforest",
+            markdown = "kanagawa",
+            python = "iceberg",
+        },
+        fallback = "solarized8",
+    },
+    timing = "bufferchanged",
+})
+```
+
 To choose a colorscheme on fixed interval per seconds, please use:
 
 ```lua

lua/colorbox.lua

@@ -12,7 +12,7 @@ local Defaults = {
     --- @alias colorbox.BuiltinPolicyConfig "shuffle"|"in_order"|"reverse_order"|"single"
     ---
     -- by filetype policy: buffer filetype => color name
-    --- @alias colorbox.ByFileTypePolicyConfig {implement:colorbox.BuiltinPolicyConfig|table<string, string>}
+    --- @alias colorbox.ByFileTypePolicyConfig {mapping:table<string, string>,fallback:string}
     ---
     -- fixed interval seconds
     --- @alias colorbox.FixedIntervalPolicyConfig {seconds:integer,implement:colorbox.BuiltinPolicyConfig}
@@ -21,7 +21,7 @@ local Defaults = {
     --- @type colorbox.PolicyConfig
     policy = "shuffle",
 
-    --- @type "startup"|"interval"|"filetype"
+    --- @type "startup"|"interval"|"bufferchanged"
     timing = "startup",
 
     -- (Optional) filters that disable some colors that you don't want.
@@ -132,8 +132,8 @@ end
 
 local function _init()
     local home_dir = vim.fn["colorbox#base_dir"]()
-    local pack_dir = "pack/colorbox/start"
-    local full_pack_dir = string.format("%s/%s", home_dir, pack_dir)
+    -- local pack_dir = "pack/colorbox/start"
+    -- local full_pack_dir = string.format("%s/%s", home_dir, pack_dir)
     -- logger.debug(
     --     "|colorbox.init| home_dir:%s, pack_dir:%s, full_pack_dir:%s",
     --     vim.inspect(home_dir),
@@ -169,23 +169,19 @@ local function _init()
     -- )
 end
 
-local function _update_background()
-    if Configs.background == "dark" or Configs.background == "light" then
-        vim.opt.background = Configs.background
-    end
-end
-
 local function _force_sync_syntax()
     vim.cmd([[syntax sync fromstart]])
 end
 
 --- @alias PreviousTrack {color_name:string,color_number:integer}
 --- @param color_name string
 local function _save_track(color_name)
-    assert(
-        type(color_name) == "string" and string.len(vim.trim(color_name)) > 0,
-        string.format("invalid color name %s", vim.inspect(color_name))
-    )
+    if
+        type(color_name) ~= "string"
+        or string.len(vim.trim(color_name)) == 0
+    then
+        return
+    end
     -- start from 0, end with #FilteredColorNamesList-1
     local color_number = FilteredColorNameToIndexMap[color_name] or 0
     vim.schedule(function()
@@ -238,8 +234,9 @@ local function _policy_shuffle()
         --     vim.inspect(ColorNames),
         --     vim.inspect()
         -- )
-        _update_background()
-        vim.cmd(string.format([[color %s]], color))
+        ---@diagnostic disable-next-line: param-type-mismatch
+        local ok, err = pcall(vim.cmd, string.format([[color %s]], color))
+        assert(ok, err)
     end
 end
 
@@ -248,8 +245,9 @@ local function _policy_in_order()
         local previous_track = _load_previous_track() --[[@as PreviousTrack]]
         local i = previous_track ~= nil and previous_track.color_number or 0
         local color = _get_next_color_name_by_idx(i)
-        _update_background()
-        vim.cmd(string.format([[color %s]], color))
+        ---@diagnostic disable-next-line: param-type-mismatch
+        local ok, err = pcall(vim.cmd, string.format([[color %s]], color))
+        assert(ok, err)
     end
 end
 
@@ -259,8 +257,9 @@ local function _policy_reverse_order()
         local i = previous_track ~= nil and previous_track.color_number
             or (#FilteredColorNamesList + 1)
         local color = _get_prev_color_name_by_idx(i)
-        _update_background()
-        vim.cmd(string.format([[color %s]], color))
+        ---@diagnostic disable-next-line: param-type-mismatch
+        local ok, err = pcall(vim.cmd, string.format([[color %s]], color))
+        assert(ok, err)
     end
 end
 
@@ -274,13 +273,15 @@ local function _policy_single()
             color = _get_next_color_name_by_idx(0)
         end
         if color ~= vim.g.colors_name then
-            _update_background()
-            vim.cmd(string.format([[color %s]], color))
+            ---@diagnostic disable-next-line: param-type-mismatch
+            local ok, err = pcall(vim.cmd, string.format([[color %s]], color))
+            assert(ok, err)
         end
     end
 end
 
 --- @param po colorbox.Options?
+--- @return boolean
 local function _is_fixed_interval_policy(po)
     return type(po) == "table"
         and type(po.seconds) == "number"
@@ -312,6 +313,39 @@ local function _policy_fixed_interval()
     impl()
 end
 
+--- @param po colorbox.Options?
+--- @return boolean
+local function _is_by_filetype_policy(po)
+    return type(po) == "table"
+        and type(po.mapping) == "table"
+        and type(po.fallback) == "string"
+        and string.len(po.fallback) > 0
+end
+
+local function _policy_by_filetype()
+    vim.defer_fn(function()
+        local ft = vim.bo.filetype or ""
+
+        if Configs.policy.mapping[ft] then
+            local ok, err = pcall(
+                ---@diagnostic disable-next-line: param-type-mismatch
+                vim.cmd,
+                string.format([[color %s]], Configs.policy.mapping[ft])
+            )
+            assert(ok, err)
+        else
+            local ok, err =
+                ---@diagnostic disable-next-line: param-type-mismatch
+                pcall(
+                    vim.cmd,
+                    string.format([[color %s]], Configs.policy.fallback)
+                )
+            assert(ok, err)
+        end
+        _force_sync_syntax()
+    end, 200)
+end
+
 local function _policy()
     if Configs.policy == "shuffle" then
         _policy_shuffle()
@@ -321,8 +355,16 @@ local function _policy()
         _policy_reverse_order()
     elseif Configs.policy == "single" then
         _policy_single()
-    elseif _is_fixed_interval_policy(Configs.policy) then
+    elseif
+        Configs.timing == "interval"
+        and _is_fixed_interval_policy(Configs.policy)
+    then
         _policy_fixed_interval()
+    elseif
+        Configs.timing == "bufferchanged"
+        and _is_by_filetype_policy(Configs.policy)
+    then
+        _policy_by_filetype()
     end
 end
 
@@ -332,8 +374,10 @@ local function _timing_startup()
     })
 end
 
-local function _timing_interval()
-    -- Configs.timing
+local function _timing_buffer_changed()
+    vim.api.nvim_create_autocmd({ "BufNew", "BufReadPre", "BufNewFile" }, {
+        callback = _policy,
+    })
 end
 
 local function _timing()
@@ -348,6 +392,17 @@ local function _timing()
             )
         )
         _policy_fixed_interval()
+    elseif Configs.timing == "bufferchanged" then
+        assert(
+            _is_by_filetype_policy(Configs.policy),
+            string.format(
+                "invalid policy %s for 'bufferchanged' timing!",
+                vim.inspect(Configs.policy)
+            )
+        )
+        _timing_buffer_changed()
+    else
+        error(string.format("invalid timing %s!", vim.inspect(Configs.timing)))
     end
 end
 
@@ -682,10 +737,10 @@ local function setup(opts)
 
     vim.api.nvim_create_autocmd("ColorSchemePre", {
         callback = function(event)
-            logger.debug(
-                "|colorbox.setup| ColorSchemePre event:%s",
-                vim.inspect(event)
-            )
+            -- logger.debug(
+            --     "|colorbox.setup| ColorSchemePre event:%s",
+            --     vim.inspect(event)
+            -- )
             local ColorNameToColorSpecsMap =
                 require("colorbox.db").get_color_name_to_color_specs_map()
             if
@@ -702,15 +757,21 @@ local function setup(opts)
             then
                 Configs.setup[spec.handle]()
             end
+            if
+                Configs.background == "dark"
+                or Configs.background == "light"
+            then
+                vim.opt.background = Configs.background
+            end
         end,
     })
 
     vim.api.nvim_create_autocmd("ColorScheme", {
         callback = function(event)
-            logger.debug(
-                "|colorbox.setup| ColorScheme event:%s",
-                vim.inspect(event)
-            )
+            -- logger.debug(
+            --     "|colorbox.setup| ColorScheme event:%s",
+            --     vim.inspect(event)
+            -- )
             _save_track(event.match)
         end,
     })