From c10e5ea70ddc1358006723977f5f1928c1f81a99 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Thu, 21 Nov 2024 11:46:45 +0000
Subject: [PATCH] set Model start/duration from points

---
 frontend/src/Main.elm  | 12 ++++++++++--
 frontend/src/Point.elm |  7 ++++++-
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/frontend/src/Main.elm b/frontend/src/Main.elm
index 27f4db2..8c487cc 100644
--- a/frontend/src/Main.elm
+++ b/frontend/src/Main.elm
@@ -158,7 +158,7 @@ init _ url navKey =
                 Just (Timeline (Just s) (Just d)) -> (s, d)
                 _ -> (10,10)
     in
-        ((Model (toCoord 51.60 -0.01) (FineZoomLevel (13*8)) None None start duration Empty),
+        ((Model (toCoord 51.60 -0.01) (FineZoomLevel (13*8)) None None 0 0 Empty),
              (fetchTrack start duration))
 
 -- SUBSCRIPTIONS
@@ -234,7 +234,15 @@ updateModel msg model =
             }
         Loaded result ->
             case result of
-                Ok trk -> { model | track = Present trk }
+                Ok trk ->
+                    let start = Maybe.withDefault 0 (Point.startTime trk)
+                        duration = Point.duration trk
+                    in
+                    { model
+                        | track = Present trk
+                        , startTime = floor start
+                        , duration = ceiling duration
+                    }
                 Err (Http.BadBody e) -> { model | track = Debug.log e (Failure "e") }
                 Err e -> { model | track = Debug.log "unknown error" (Failure "e") }
         NewUrlRequest -> model
diff --git a/frontend/src/Point.elm b/frontend/src/Point.elm
index f33ab99..6179249 100644
--- a/frontend/src/Point.elm
+++ b/frontend/src/Point.elm
@@ -1,4 +1,4 @@
-module Point exposing(Pos, Point, decoder, downsample, duration, subseq)
+module Point exposing(Pos, Point, decoder, downsample, duration, subseq, startTime)
 
 import Json.Decode as D
 
@@ -63,6 +63,11 @@ duration points =
         (p::ps) -> (last p ps).time - p.time
         _ -> 0
 
+startTime points =
+    case points of
+        (p::ps) -> Just p.time
+        _ -> Nothing
+
 subseq points start dur =
     case points of
         [] -> []