```{r}
library(tidyr)
library(dplyr)
library(terra)
library(mregions2)
library(biooracler)
library(stringr)
library(tibble)
library(catboost)
library(caret)
library(blockCV)
library(sf)
library(usdm)
library(ggcorrplot)
library(reshape2)
library(tidygraph)
library(ggraph)
library(CAST)
library(pdp)
library(ggplot2)
library(DALEX)
```


```{r}
seal_range = vect("data/iucn/Pagophilus_groenlandicus.shp")
bbox = ext(seal_range) |> extend(5)

lon_range = c(bbox$xmin, bbox$xmax)
lat_range = c(bbox$ymin, bbox$ymax)

constraints = list(
    longitude = lon_range,
    latitude = lat_range
)
```


```{r}
layers = list_layers()

# Нет прогнозных данных :/
removed_layers_ids = c(
    "par_mean_baseline_2000_2020_depthsurf",
    "kdpar_mean_baseline_2000_2020_depthsurf",
    "chl_baseline_2000_2018_depthmax",
    "chl_baseline_2000_2018_depthmean",
    "chl_baseline_2000_2018_depthmin"
)

constant_layers_ids = c("terrain_characteristics")

constant_layers = layers |>
    filter(dataset_id %in% constant_layers_ids)
```

```{r}
dynamic_layers = layers |>
    filter(! dataset_id %in% c(constant_layers_ids, removed_layers_ids)) |> 
    separate_wider_delim(dataset_id, delim = "_", names = c("var", "scenario", "year_star", "year_end", "depth"), cols_remove = FALSE)
```

```{r}
download_slice = function(scenario_value, decade_start) {
    scenario_layers = dynamic_layers |> 
        filter(scenario == scenario_value)

    time_point = paste0(decade_start, "-01-01T00:00:00Z")

    slice_constraints = list(
        time = c(time_point, time_point),
        longitude = lon_range,
        latitude = lat_range
    )

    download_dir = file.path("./data/bio-oracle-2", scenario_value, decade_start)
    dir.create(download_dir, recursive = TRUE, showWarnings = FALSE)

    slice_rasters = sapply(
        scenario_layers$dataset_id,
        function(id) download_layers(
            id,
            constraints = slice_constraints,
            directory = download_dir
        ),
        simplify = TRUE
    )

    return(slice_rasters)
}
```

```{r}
baseline_rasters = download_slice("baseline", 2010)
```

```{r}
baseline_brick = rast(baseline_rasters)
baseline_brick_depths = baseline_brick |> 
    names() |> 
    str_extract("depth[:alpha:]+")
baseline_brick_longnames = baseline_brick |> longnames()
baseline_brick_varnames = baseline_brick |> varnames()
```

```{r}
subset_baseline_layer_names = tibble(
    name = names(baseline_brick),
    longname = baseline_brick_longnames,
    varname = baseline_brick_varnames,
    depth = baseline_brick_depths
) |> 
    separate_wider_delim(
        varname,
        delim = "_",
        names = c("var", "type")
    ) |> 
        filter(
            !(
                depth == "depthmax" |
                var %in% c("ph", "si", "dfe", "no3", "po4", "clt", "o2", "mlotst", "sws", "swd", "so") |
                type %in% c("ltmin", "ltmax", "range")
            )
        )
```

```{r}
subset_baseline_brick = baseline_brick |> 
    subset(subset_baseline_layer_names$name)
```

```{r}
names(baseline_brick) = paste(baseline_brick_longnames, baseline_brick_depths)
```

```{r}
# features_brick = c(baseline_brick, terrain_raster)
features_brick = c(subset_baseline_brick)
```

```{r}
cropped_bbox = ext(
    -20,
    72,
    60,
    85
)
```

```{r}
cropped_features_brick = features_brick |> 
    crop(cropped_bbox)
```

```{r}
baseline_df = cropped_features_brick |> 
    as.data.frame(cells = TRUE, xy = TRUE)
```

```{r}
vif_input_df <- baseline_df |>
  select(-cell) |> 
  drop_na()
```

```{r}
vif_sample = vif_input_df |> 
  sample_n(10000)

vif_sample = vif_sample[, sapply(vif_sample, function(x) var(x) > 0)]
```

```{r}
corr_matrix <- cor(vif_sample)

ggcorrplot(corr_matrix, 
        #    hc.order = TRUE,   # Clusters similar variables together
           type = "lower",    # Only show half (it's symmetrical anyway)
           outline.col = "white",
           colors = c("#6D9EC1", "white", "#E46726"),
           lab = FALSE) +     # Set to TRUE only if you have <20 variables
  theme(axis.text.x = element_text(size = 7, angle = 90),
        axis.text.y = element_text(size = 7))
```

```{r}
high_cor_pairs <- melt(corr_matrix) |>
  filter(abs(value) > 0.8) |>
  filter(Var1 != Var2) |>              # Remove self-correlations (1.0 on diagonal)
  distinct(value, .keep_all = TRUE) |> # Remove duplicates (A-B and B-A)
  arrange(desc(abs(value))) |> 
  mutate(Var1 = as.character(Var1),
         Var2 = as.character(Var2))
```

```{r}
graph_data <- as_tbl_graph(high_cor_pairs)

# Plot the clusters
ggraph(graph_data, layout = "nicely") +
  geom_edge_link(aes(alpha = abs(value)), color = "orange") +
  geom_node_point(size = 2, color = "steelblue") +
  geom_node_text(aes(label = name), repel = TRUE, size = 5) +
  theme_void() +
  labs(title = "Network of Redundant Variables (|r| > 0.8)")
```

```{r}
vif_results <- vifstep(vif_sample, th = 10)
```


```{r}
keeper_vars <- vif_results@results$Variables
```


```{r}
baseline_df_subset = baseline_df |> 
    select(cell, x, y, keeper_vars)
```

```{r}
cropped_seal_range_raster = seal_range |> 
    rasterize(cropped_features_brick[[1]], field="", background=0)
```

```{r}
cropped_seal_range_df = cropped_seal_range_raster |> 
    as.data.frame(cells = TRUE) |> 
    rename(target = layer)
```

```{r}
seal_baseline = dplyr::left_join(baseline_df_subset, cropped_seal_range_df, by = "cell")
```

```{r}
seal_baseline_sf = st_as_sf(seal_baseline, coords = c("x", "y"), crs = 4326)
```


```{r}
sb <- cv_spatial(x = seal_baseline_sf, 
                column = "target", 
                size = 500000,
                k = 3, 
                selection = "random")
```


```{r}
seal_baseline$block_id <- sb$folds_ids
seal_baseline$target <- as.factor(make.names(seal_baseline$target))
```

```{r}
# save(seal_baseline, file = "seal_baseline.Rda")
load(file = "seal_baseline.Rda")
```


```{r}
indices <- CAST::CreateSpacetimeFolds(seal_baseline, 
                                spacevar = "block_id", 
                                k = 3)
```

```{r}
seal_baseline_sample = sample_n(seal_baseline, 100000)
```


```{r}
ctrl <- trainControl(method = "cv", 
                     index = indices$index, 
                     indexOut = indices$indexOut,
                     classProbs = TRUE,
                     summaryFunction = twoClassSummary,
                     verboseIter = TRUE)

ffs_model <- ffs(
  predictors = seal_baseline |> select(-cell, -x, -y, -target),
  response = seal_baseline$target,
  method = "ranger", 
  metric = "ROC",
  trControl = ctrl,
  tuneGrid = expand.grid(mtry = 2, 
                         splitrule = "gini", 
                         min.node.size = 10),
  num.trees = 50,
  num.threads = parallel::detectCores() - 1,
  withinSE = TRUE,
  minDiff = 0.005,
  )
```


```{r}
# save(ffs_model, file = "ffs_model.Rda")
load(file = "ffs_model.Rda")
```


```{r}
# 1. Take a small, representative sample for the calculation
pdp_sample <- seal_baseline[sample(nrow(seal_baseline), 500), ]

# 2. Run the partial function with 'train = pdp_sample' and 'grid.resolution'
pdp_temp <- partial(ffs_model, 
                    pred.var = "Minimum OceanTemperature depthsurf", 
                    prob = TRUE, 
                    which.class = "X1", 
                    train = pdp_sample,     # This is the secret to speed
                    grid.resolution = 20)   # 20 points is plenty for a smooth line
```

```{r}
# 3. Plot it
autoplot(pdp_temp) + theme_minimal()
```


```{r}
# 2. Create the plot
# The 'rug = TRUE' adds little tick marks at the bottom showing 
# where your actual data points sit.
autoplot(pdp_temp, rug = TRUE, train = seal_baseline) +
  theme_minimal() +
  labs(title = "Partial Dependence: Min Ocean Temperature",
       subtitle = "How Ocean Temp influences Seal Presence Probability",
       x = "Temperature (°C)",
       y = "Probability of Presence") +
  geom_line(size = 1.2, color = "steelblue")
```

```{r}
final_vars <- c(
  "Minimum Chlorophyll depthsurf",
  "Maximum TotalPhytoplankton depthsurf",
  "Maximum AirTemperature depthsurf",
  "Minimum OceanTemperature depthsurf",
  "Average Chlorophyll depthsurf",
  "Maximum OceanTemperature depthmean",
  "Average TotalPhytoplankton depthmean"
)
```

```{r}
train_data <- seal_baseline %>%
  mutate(target_num = ifelse(target == "X1", 1, 0))
```

```{r}
unique_blocks <- unique(train_data$block_id)
train_blocks <- sample(unique_blocks, size = round(0.7 * length(unique_blocks)))

# 3. Create the dataframes based on the blocks
train_df <- train_data %>% filter(block_id %in% train_blocks)
test_df  <- train_data %>% filter(!(block_id %in% train_blocks))
```

```{r}
train_pool <- catboost.load_pool(
  data = train_df[, final_vars], 
  label = train_df$target_num
)

test_pool = catboost.load_pool(
  data = test_df[, final_vars], 
  label = test_df$target_num
)
```

```{r}
params <- list(
  loss_function = 'Logloss',
  eval_metric = 'AUC',
  iterations = 100,     # Plenty of trees for a smooth fit
  depth = 3,             # Standard depth to prevent overfitting
  learning_rate = 0.06,  # Lower learning rate is better for high ROC data
  l2_leaf_reg = 30,       # Stronger regularization to handle that 0.998 ROC
  random_seed = 42,
  rsm = 0.5,
  verbose = 10          # Log progress every 100 iterations
)
```

```{r}
cat_model <- catboost.train(train_pool, test_pool = test_pool, params = params)
```

```{r}
explainer_cat <- explain(
  model = cat_model,
  data = train_df[, final_vars],
  y = train_df$target_num,
  label = "CatBoost Harp Seal Model",
  predict_function = function(model, x) catboost.predict(model, catboost.load_pool(x), prediction_type = "Probability")
)
```
```{r}
pdp_temp <- model_profile(
  explainer = explainer_cat,
  variables = "Minimum OceanTemperature depthsurf"
)

# 3. Plot it
plot(pdp_temp)
```

```{r}
importanc2e <- catboost.get_feature_importance(cat_model, train_pool)
```