Merge pull request #24 from mhiro2/refactor/split-stack-view-pipeline

refactor(ui): Split stack view state and modularize the render pipeline

Author: mhiro2

lua/peekstack/types.lua

@@ -161,6 +161,32 @@
 ---@field help_augroup integer?
 ---@field autoclose_group integer?
 ---@field autoclose_suspended integer
+---@field preview_ts_cache table<string, PeekstackStackViewPreviewTsHighlight[]|false>
+
+---@class PeekstackStackViewHighlight
+---@field col_start integer
+---@field col_end integer
+---@field hl_group string
+
+---@class PeekstackStackViewPreviewLine
+---@field line string
+---@field source_bufnr integer
+---@field source_line integer
+---@field source_col_start integer
+---@field source_col_end integer
+---@field preview_col_start integer
+
+---@class PeekstackStackViewPreviewTsHighlight
+---@field start_offset integer
+---@field end_offset integer
+---@field hl_group string
+
+---@class PeekstackStackViewRenderModel
+---@field lines string[]
+---@field highlights PeekstackStackViewHighlight[][]
+---@field preview_lines table<integer, PeekstackStackViewPreviewLine>
+---@field line_to_id table<integer, integer>
+---@field header_lines integer
 
 -- Config type definitions
 

lua/peekstack/ui/stack_view/diff.lua

@@ -0,0 +1,146 @@
+local preview = require("peekstack.ui.stack_view.preview")
+
+local M = {}
+
+local NS = vim.api.nvim_create_namespace("PeekstackStackView")
+local PREVIEW_BASE_HL_PRIORITY = 10
+
+---@param line string
+---@param line_hls PeekstackStackViewHighlight[]
+---@param preview_line PeekstackStackViewPreviewLine?
+---@return string
+local function line_render_key(line, line_hls, preview_line)
+  local parts = { line }
+  for _, hl in ipairs(line_hls) do
+    parts[#parts + 1] = string.format("%d:%d:%s", hl.col_start, hl.col_end, hl.hl_group)
+  end
+  if preview_line then
+    parts[#parts + 1] = string.format(
+      "preview:%d:%d:%d:%d:%d",
+      preview_line.source_bufnr,
+      preview_line.source_line,
+      preview_line.source_col_start,
+      preview_line.source_col_end,
+      preview_line.preview_col_start
+    )
+  end
+  return table.concat(parts, "|")
+end
+
+---@param items string[]
+---@param start_idx integer
+---@param end_idx integer
+---@return string[]
+local function slice_lines(items, start_idx, end_idx)
+  if end_idx < start_idx then
+    return {}
+  end
+
+  ---@type string[]
+  local slice = {}
+  for idx = start_idx, end_idx do
+    slice[#slice + 1] = items[idx]
+  end
+  return slice
+end
+
+---@param old_keys string[]
+---@param new_keys string[]
+---@return integer?, integer?, integer?
+local function diff_range(old_keys, new_keys)
+  local old_count = #old_keys
+  local new_count = #new_keys
+  local start_idx = 1
+
+  while start_idx <= old_count and start_idx <= new_count and old_keys[start_idx] == new_keys[start_idx] do
+    start_idx = start_idx + 1
+  end
+
+  if start_idx > old_count and start_idx > new_count then
+    return nil, nil, nil
+  end
+
+  local old_end = old_count
+  local new_end = new_count
+  while old_end >= start_idx and new_end >= start_idx and old_keys[old_end] == new_keys[new_end] do
+    old_end = old_end - 1
+    new_end = new_end - 1
+  end
+
+  return start_idx, old_end, new_end
+end
+
+---@param bufnr integer
+---@param highlights PeekstackStackViewHighlight[][]
+---@param preview_lines table<integer, PeekstackStackViewPreviewLine>
+---@param start_idx integer
+---@param end_idx integer
+---@param preview_cache table<string, PeekstackStackViewPreviewTsHighlight[]|false>
+local function apply_highlights_in_range(bufnr, highlights, preview_lines, start_idx, end_idx, preview_cache)
+  if end_idx < start_idx then
+    return
+  end
+
+  for line_idx = start_idx, end_idx do
+    for _, hl in ipairs(highlights[line_idx] or {}) do
+      local opts = {
+        end_col = hl.col_end,
+        hl_group = hl.hl_group,
+      }
+      if hl.hl_group == "PeekstackStackViewPreview" then
+        opts.priority = PREVIEW_BASE_HL_PRIORITY
+      end
+      vim.api.nvim_buf_set_extmark(bufnr, NS, line_idx - 1, hl.col_start, {
+        end_col = opts.end_col,
+        hl_group = opts.hl_group,
+        priority = opts.priority,
+      })
+    end
+  end
+
+  ---@type table<integer, PeekstackStackViewPreviewLine>
+  local changed_previews = {}
+  for line_idx = start_idx, end_idx do
+    if preview_lines[line_idx] then
+      changed_previews[line_idx] = preview_lines[line_idx]
+    end
+  end
+  if next(changed_previews) then
+    preview.apply_treesitter_highlights(bufnr, changed_previews, preview_cache)
+  end
+end
+
+---@param model PeekstackStackViewRenderModel
+---@return string[]
+local function line_keys(model)
+  ---@type string[]
+  local keys = {}
+  for line_idx, line in ipairs(model.lines) do
+    keys[line_idx] = line_render_key(line, model.highlights[line_idx] or {}, model.preview_lines[line_idx])
+  end
+  return keys
+end
+
+---@param bufnr integer
+---@param old_keys string[]
+---@param model PeekstackStackViewRenderModel
+---@param preview_cache table<string, PeekstackStackViewPreviewTsHighlight[]|false>
+---@return string[]
+function M.apply(bufnr, old_keys, model, preview_cache)
+  local new_keys = line_keys(model)
+  local start_idx, old_end, new_end = diff_range(old_keys, new_keys)
+  if start_idx then
+    local replace = slice_lines(model.lines, start_idx, new_end)
+
+    vim.bo[bufnr].modifiable = true
+    vim.api.nvim_buf_set_lines(bufnr, start_idx - 1, old_end, false, replace)
+    vim.bo[bufnr].modifiable = false
+
+    vim.api.nvim_buf_clear_namespace(bufnr, NS, start_idx - 1, old_end)
+    apply_highlights_in_range(bufnr, model.highlights, model.preview_lines, start_idx, new_end, preview_cache)
+  end
+
+  return new_keys
+end
+
+return M