Dashboard: Add configurable quick ranges for the time picker (#102254)

* Dashboard: Add configurable quick ranges for the time picker

* fix test and linter errors

* update from array to TimeOption

* Switching to grafana-scenes (Part 1 - remove grafana-ui changes

* Update SceneTimePicker initialization

* betterer

* remove hallucinated argument

* Revert "Bump scenes and fix types (#105167)"

This reverts commit c6428dfc74.

* make gen-go

* reset files

* Shorten documentation to increase maintainability

* Update _index.md

* the

---------

Co-authored-by: joshhunt <josh.hunt@grafana.com>
Co-authored-by: Jacob Valdez <jacob.valdez@grafana.com>

pkg/setting/setting_time_picker.go

@@ -0,0 +1,57 @@
+package setting
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// QuickRanges is a slice of QuickRange objects that can be directly used in frontend
+type QuickRanges []QuickRange
+
+// QuickRange represents a time range option in the time picker.
+// It defines a preset time range that users can select from the time picker dropdown.
+type QuickRange struct {
+	// Display is the user-friendly label shown in the UI for this time range
+	Display string `json:"display"`
+	// From is the start of the time range in a format like "now-6h" or an absolute time
+	From string `json:"from"`
+	// To is the end of the time range, defaults to "now" if omitted
+	To string `json:"to,omitempty"`
+}
+
+func (cfg *Cfg) readTimePicker() error {
+	timePickerSection := cfg.Raw.Section("time_picker")
+	quickRangesStr := timePickerSection.Key("quick_ranges").String()
+
+	if quickRangesStr == "" {
+		cfg.QuickRanges = []QuickRange{}
+		return nil
+	}
+
+	var quickRanges []QuickRange
+	err := json.Unmarshal([]byte(quickRangesStr), &quickRanges)
+	if err != nil {
+		cfg.Logger.Error("Failed to parse quick_ranges", "error", err)
+		return fmt.Errorf("failed to parse quick_ranges: %w", err)
+	}
+
+	// Validate the quick ranges and set defaults
+	for i, qr := range quickRanges {
+		if qr.Display == "" {
+			cfg.Logger.Error("Quick range is missing display name", "index", i)
+			return fmt.Errorf("quick range at index %d is missing display name", i)
+		}
+		if qr.From == "" {
+			cfg.Logger.Error("Quick range is missing 'from' field", "display", qr.Display)
+			return fmt.Errorf("quick range '%s' is missing 'from' field", qr.Display)
+		}
+		// Set default value for To field if it's empty
+		if qr.To == "" {
+			quickRanges[i].To = "now"
+		}
+	}
+
+	cfg.QuickRanges = quickRanges
+
+	return nil
+}