Merge 82801c52bc into dacebf94bc

res/modules/search_utils.lua

@@ -0,0 +1,102 @@
+local M = {}
+
+M.MATCHED_COLOR_DEFAULT = "[#4FC3F7]"
+M.NORMAL_COLOR_DEFAULT = "[#FFFFFF]"
+
+---Calculate fuzzy score
+---@param sample str
+---@param pattern str
+---@param do_coloring? bool if passed, then function will also return colored_sample, where matched
+---characters batched will be wrapped in color_matched and color_normal strings
+---@param color_matched? str if not passed, uses the default M.MATCHED_COLOR_DEFAULT
+---@param color_normal? str if not passed, uses the default M.NORMAL_COLOR_DEFAULT
+---@return int match pattern match intensity, 0 for absence
+---@return str? colored_sample
+function M.fuzzy_score(sample, pattern, do_coloring, color_matched, color_normal)
+    if pattern == "" then return 0 end
+
+    color_matched = color_matched or M.MATCHED_COLOR_DEFAULT
+    color_normal = color_normal or M.NORMAL_COLOR_DEFAULT
+    local colored_sample
+    if do_coloring then
+        colored_sample = ""
+    end
+
+    local sample_lower = string.lower(sample)
+    local pattern_lower = string.lower(pattern)
+
+    local sample_len = #sample_lower
+    local pattern_len = #pattern_lower
+
+    if pattern_len > sample_len then return 0 end
+
+    local pattern_idx = 1
+    local consecutive = 0
+    local max_consecutive = 0
+    local matched_chars = 0
+    local total_distance = 0
+    local last_match_pos = -1
+
+    for i = 1, sample_len do
+        if pattern_idx <= pattern_len and (
+                sample_lower:sub(i, i) ==
+                pattern_lower:sub(pattern_idx, pattern_idx)) then
+            matched_chars = matched_chars + 1
+            if consecutive == 0 and do_coloring then
+                colored_sample = colored_sample .. color_matched
+            end
+            consecutive = consecutive + 1
+            if consecutive > max_consecutive then
+                max_consecutive = consecutive
+            end
+
+            if last_match_pos ~= -1 then
+                total_distance = total_distance + (i - last_match_pos - 1)
+            end
+            last_match_pos = i
+
+            pattern_idx = pattern_idx + 1
+        else
+            if consecutive ~= 0 and do_coloring then
+                colored_sample = colored_sample .. color_normal
+            end
+            consecutive = 0
+        end
+        if do_coloring then
+            colored_sample = colored_sample .. sample:sub(i, i)
+        end
+    end
+    if consecutive ~= 0 and do_coloring then
+        colored_sample = colored_sample .. color_normal
+    end
+
+    if pattern_idx <= pattern_len then
+        return 0
+    end
+
+    local coverage = matched_chars / pattern_len * 20
+
+    local consecutive_bonus = max_consecutive * 10
+
+    local start_bonus = 0
+    if sample_lower:sub(1, 1) == pattern_lower:sub(1, 1) then
+        start_bonus = 15
+    end
+
+    local prefix_bonus = 0
+    if sample_lower:find(pattern_lower, 1, true) == 1 then
+        prefix_bonus = 25
+    end
+
+    local distance_penalty = total_distance * 2
+
+    local score = coverage + consecutive_bonus + start_bonus + prefix_bonus - distance_penalty
+
+    if sample_lower:find(pattern_lower, 1, true) then
+        score = score + 30
+    end
+
+    return math.max(0, score), colored_sample
+end
+
+return M