sequenceDiagram
    participant Parent as Parent (User Page)
    participant Embed as Embed (iframe)
    participant Store as EmbedStore(iframe)
    participant UI as UI Components(iframe)
    
    Note over Parent: embed.js loads
    
    alt CTA clicked or Cal.modal() called
        Parent->>Parent: Check for existing modal
        alt Modal exists & can reuse
            Parent->>Parent: Reopen modal (state: "reopened")
            Note over Parent: May use connect() or reload
        else Create new modal
            Parent->>Parent: Create cal-modal-box
            Parent->>Parent: Create iframe (hidden)
            Parent->>Parent: Set state="loading"
            Parent->>Parent: Show loader
        end
    end
    
    Note over Embed: background: transparent
    Note over Embed: body tag hidden
    Note over Embed: iframe webpage starts rendering
    
    Note over Store: EmbedStore pre-initialized<br/>State: NOT_INITIALIZED
    Store->>Store: Initialize UI config & theme
    
    Note over Parent: Process URL params for prefill
    Parent->>Store: Set prefill data from URL
    
    Embed->>Parent: __iframeReady event
    Note right of Embed: Purpose: Signals iframe is ready<br/>to receive messages from parent<br/>Action: Makes iframe visible<br/>(unless prerendering),<br/>processes queued commands
    Note over Parent: Sets iframeReady flag
    Note over Parent: Makes iframe visible (unless prerendering)
    Note over Store: Set state to INITIALIZED
    
    Store->>UI: Apply theme & cssVarsPerTheme
    
    Embed->>Parent: __dimensionChanged event
    Note right of Embed: Purpose: Keeps iframe size<br/>matched to content<br/>Triggers: Content size changes,<br/>page finishes loading
    Note over Parent: Adjust iframe dimensions
    Note over Store: Update providedCorrectHeightToParent
    
    Embed->>Parent: __windowLoadComplete event
    Note right of Embed: Purpose: Signals page fully loaded<br/>Ensures dimension calculations<br/>are reliable
    
    alt isBookerPage with skeleton
        Note over Embed: Wait for slotsDone state
    end
    
    Embed->>Parent: linkReady event
    Note right of Embed: Purpose: Signals iframe content<br/>is fully ready for interaction<br/>Requirements: Height known,<br/>slots loaded (if skeleton)
    Note over Parent: Remove loader
    Note over Parent: Set state="loaded"
    Note over Parent: Make iframe visible
    
    Parent->>Embed: parentKnowsIframeReady event
    Note right of Parent: Purpose: Parent acknowledges<br/>iframe readiness<br/>Action: Makes body visible,<br/>sets renderState completed
    Note over Embed: Makes body visible
    Note over Store: renderState: "completed"
    
    loop Dimension Monitoring
        Embed->>Embed: Monitor content size changes
        alt Dimensions Changed
            Embed->>Parent: __dimensionChanged event
            Note right of Embed: Purpose: Maintain proper sizing<br/>as content changes
            Parent->>Parent: Adjust iframe size
        end
    end
    
    alt Route Changes
        UI->>Store: Update UI state
        Store->>Parent: __routeChanged event
        Note right of Store: Purpose: Notifies parent of<br/>navigation within embed<br/>Action: Handle navigation
        Note over Parent: Handle navigation
    end
    
    alt Booker Events (Tracking)
        UI->>Store: Update viewId on linkReady
        UI->>Parent: bookerViewed event
        Note right of UI: Purpose: Tracks first view of booker<br/>on first modal open<br/>Includes: Event info, slots status<br/>Not fired during prerendering
        UI->>Parent: bookerReady event
        Note right of UI: Purpose: Signals booker view is loaded<br/>and slots are ready for interaction<br/>Includes: Event identification<br/>Only fires for booker pages
        alt User closes and reopens modal
            UI->>Parent: bookerReopened event
            Note right of UI: Purpose: Tracks when booker is<br/>reopened after being closed<br/>Distinguishes from first view
        end
        alt Full reload scenario
            Parent->>Embed: __reloadInitiated method
            Note right of Parent: Purpose: Notify iframe that<br/>fullReload is happening<br/>Action: Set reloadInitiated flag
            Note over Store: reloadInitiated: true
            UI->>Parent: bookerReloaded event
            Note right of UI: Purpose: Tracks when booker is<br/>reloaded (full page reload)<br/>Distinguishes from reopen
            Note over Store: Reset reloadInitiated flag
        end
    end
    
    alt Close Request
        Embed->>Parent: __closeIframe event
        Note right of Embed: Purpose: Request to close modal<br/>from within iframe<br/>Action: Set state="closed"
        Note over Parent: Set state="closed"
    end
    
    alt Error Handling
        Embed->>Parent: linkFailed event
        Note right of Embed: Purpose: Signals page load error<br/>Includes: Error code, URL info<br/>Action: Show error state
        Note over Parent: Set state="failed"
    end