# Buyer-Seller-Appraiser Bargaining Experiment

Built with **oTree 6.0.2**.

## Setup

```bash
pip install otree==6.0.2
cd bargaining_experiment
otree devserver
```

Open http://localhost:8000 and start a demo session with **3 participants**.

---

## Game Flow

### Stage 0 – Role Assignment (all players)
Roles are randomly assigned: **Buyer**, **Seller**, **Appraiser**.

---

### Stage 1 – Practice Round (Buyer & Seller; Appraiser waits)
- Each player sees a slider from 0–400.
- They must drag the thumb to their assigned **target value** (Buyer: 250, Seller: 150).
- The **Submit** button is disabled until the target is matched exactly.
- The Appraiser sees a wait page.

---

### Stage 2 – Anonymous Offer Round (Buyer & Seller; Appraiser waits)
- Each player privately enters a price between 0 and 400.
- Neither can see the other's offer.
- A slider is provided as a UX aid but a numeric input is also accepted.
- **If Buyer price ≥ Seller price → instant deal** (average of the two prices).  
  The game jumps directly to the Final Results page.
- **Otherwise** → proceed to the Public Bargaining phase.

---

### Stage 3 – Public Bargaining (Buyer & Seller; Appraiser has own page)

#### Buyer & Seller
- Both see a **shared price line** with two coloured thumbs:
  - 🔵 **Blue** = Buyer's current position
  - 🔴 **Red**  = Seller's current position
- Initial positions are set to their anonymous offer values.
- Each player controls **only their own thumb** via their personal slider below the line.
- Positions broadcast to both players in real-time via oTree Live Pages (WebSocket).
- A **green overlap zone** appears when the buyer position ≥ seller position, indicating a potential deal.

**Round ends when ANY of the following occur:**

| Condition | Timer |
|-----------|-------|
| Buyer pos ≥ Seller pos | Immediate deal |
| No movement by either party for **10 seconds** | Idle timeout |
| **60 seconds** elapsed | Round timer |

Three on-screen timers are shown:
- ⏱ **Time Remaining** (counts down from 60s, turns red below 10s)
- ⏸ **Your Idle Time** (resets on any movement, turns red near 10s)
- ✅ **Total Time** (counts up)

All timing values (idle time, time in round, total time) are saved to the database.

#### Appraiser
- Sees their own price line (100–400) with their randomly assigned appraiser price shown as a purple marker.
- Does **not** interact with the bargaining.
- Waits for the bargaining phase to complete.

---

### Stage 4 – Final Results (all players)
Displays:
- Outcome (instant deal / bargaining deal / no deal)
- Final price (if deal)
- Total time, idle time, time in round
- Appraiser's price (for Appraiser role)

---

## File Structure

```
bargaining_experiment/
├── settings.py
└── bargaining_game/
    ├── __init__.py          ← Models, pages, live methods
    └── templates/
        └── bargaining_game/
            ├── RoleAssignment.html
            ├── PracticeSlider.html
            ├── AnonymousOffer.html
            ├── InstantDealResult.html
            ├── BargainingPage.html       ← Main real-time page
            ├── AppriserBargainingPage.html
            └── FinalResults.html
```

## Key Implementation Notes

- **Live Pages**: `BargainingPage` uses `live_method` in `__init__.py` with `liveSend` / `liveRecv` in JS for real-time position updates.
- **Timing**: All timing is done client-side (JS `setInterval`) and reported to the server via `liveSend`. The server stores values in the Player/Group models.
- **Broadcast**: Sending to player id `0` in the live_method return dict broadcasts to the whole group.
- **Idle detection**: Resets `lastMoveTime` on every `input` event; the ticker compares elapsed time since last move.