# ============================================================================
# SCRIPT 40: Weekly Mosaic Creation (CI Band Aggregation)
# ============================================================================
# PURPOSE:
#   Create weekly 5-band (R, G, B, NIR, CI) mosaics from daily satellite
#   imagery. Aggregates multi-day CI data into single weekly composite raster
#   for field-level analysis. Supports per-field or single-file architectures.
#
# INPUT DATA:
#   - Daily per-field TIFFs: laravel_app/storage/app/{project}/daily_tiles/{YYYY-MM-DD}/*.tif
#     (or single-file mosaics: merged_tif/{YYYY-MM-DD}.tif + pivot.geojson masking)
#   - CI data (RDS): laravel_app/storage/app/{project}/combined_CI/combined_CI_data.rds
#   - Field boundaries: laravel_app/storage/app/{project}/pivot.geojson
#
# OUTPUT DATA:
#   - Destination: laravel_app/storage/app/{project}/weekly_mosaic/
#   - Format: 5-band GeoTIFF (uint16)
#   - Naming: week_{WW}.tif (week number + year, e.g., week_35_2025.tif)
#   - Spatial: Raster aligned to field boundaries; CRS preserved
#
# USAGE:
#   Rscript 40_mosaic_creation.R [end_date] [offset] [project] [file_name] [data_source]
#
#   Example (Windows PowerShell):
#   & "C:\Program Files\R\R-4.4.3\bin\x64\Rscript.exe" r_app/40_mosaic_creation.R 2026-01-12 7 aura
#
# PARAMETERS:
#   - end_date: End date (YYYY-MM-DD format); required for weekly aggregation
#   - offset: Days to look back (typically 7 for one week)
#   - project: Project name (aura, angata, chemba, xinavane, esa, simba)
#   - file_name: Custom output filename (optional; default: week_{WW}_{YYYY}.tif)
#   - data_source: Data folder (optional; auto-detects merged_tif or merged_tif_8b)
#
# CLIENT TYPES:
#   - cane_supply (ANGATA): Yes - harvest readiness timeline depends on weekly mosaic
#   - agronomic_support (AURA): Yes - KPI calculation requires weekly CI bands
#
# DEPENDENCIES:
#   - Packages: sf, terra, tidyverse, lubridate, here
#   - Utils files: parameters_project.R, 00_common_utils.R, 40_mosaic_creation_utils.R
#   - Input data: Daily per-field TIFFs (Script 10) + CI extraction (Script 20)
#   - Data: field boundaries (pivot.geojson), harvest dates (if available)
#
# NOTES:
#   - Weekly aggregation: Combines 7 days of daily data into single composite
#   - 5-band output: R, G, B, NIR, and Canopy Index (CI) derived from NDVI
#   - Tiling support: Handles per-field TIFF architecture; auto-mosaics if needed
#   - Data source auto-detection: Searches merged_tif/ or merged_tif_8b/ folders
#   - Command-line driven: Designed for batch scheduling (cron/Task Scheduler)
#   - Downstream: Script 80 (KPI calculation) depends on weekly_mosaic/ output
#   - Performance: Multi-file mosaicing (~25 fields) takes 5-10 minutes per week
#
# RELATED ISSUES:
#   SC-113: Script header standardization
#   SC-112: Utilities restructuring
#   SC-111: Script 10 geometry validation
#
# ============================================================================

# 1. Load required packages
# -----------------------
suppressPackageStartupMessages({
  # File path handling
  library(here)       # For relative path resolution (platform-independent file paths)
  
  # Spatial data handling
  library(sf)         # For spatial operations (field boundary masking)
  library(terra)      # For raster operations (reading/writing/stacking GeoTIFFs)
  
  # Data manipulation
  library(tidyverse)  # For dplyr, readr (data wrangling)
  library(lubridate)  # For date/time operations (week extraction, date formatting)
})

# 2. Process command line arguments and run mosaic creation
# ------------------------------------------------------
main <- function() {
  # Capture command line arguments
  args <- commandArgs(trailingOnly = TRUE)
  
    # Process project_dir argument with default
  if (length(args) >= 3 && !is.na(args[3])) {
    project_dir <- as.character(args[3])
  } else if (exists("project_dir", envir = .GlobalEnv)) {
    project_dir <- get("project_dir", envir = .GlobalEnv)
  } else {
    # Default project directory
    project_dir <- "angata"
    message("No project_dir provided. Using default:", project_dir)
  }
  
  # Make project_dir available globally so parameters_project.R can use it
  assign("project_dir", project_dir, envir = .GlobalEnv)
  
  # Process end_date argument with default
  if (length(args) >= 1 && !is.na(args[1])) {
    # Parse date explicitly in YYYY-MM-DD format from command line
    end_date <- as.Date(args[1], format = "%Y-%m-%d")
    if (is.na(end_date)) {
      message("Invalid end_date provided. Using current date.")
      end_date <- Sys.Date()
    }
  } else if (exists("end_date_str", envir = .GlobalEnv)) {
    end_date <- as.Date(get("end_date_str", envir = .GlobalEnv))
  } else {
    # Default to current date if no argument is provided
    end_date <- Sys.Date()
    message("No end_date provided. Using current date: ", format(end_date))
  }
  
  # Process offset argument with default
  if (length(args) >= 2 && !is.na(args[2])) {
    offset <- as.numeric(args[2])
    if (is.na(offset) || offset <= 0) {
      message("Invalid offset provided. Using default (7 days).")
      offset <- 7
    }
  } else {
    # Default to 7 days if no argument is provided
    offset <- 7
    message("No offset provided. Using default:", offset, "days")
  }
  
  # Process data_source argument (optional, passed from pipeline)
  # If provided, use it; otherwise auto-detect
  data_source_from_args <- NULL
  if (length(args) >= 5 && !is.na(args[5]) && nchar(args[5]) > 0) {
    data_source_from_args <- as.character(args[5])
    message("Data source explicitly provided via arguments: ", data_source_from_args)
  }
  
  # 3. Initialize project configuration
  # --------------------------------
  
  # Detect which data source directory exists (merged_tif or merged_tif_8b)
  # IMPORTANT: Only consider a folder as valid if it contains actual files
  laravel_storage <- here::here("laravel_app/storage/app", project_dir)
  
  # Load centralized path structure
  tryCatch({
    source("r_app/parameters_project.R")
    paths <- setup_project_directories(project_dir)
  }, error = function(e) {
    message("Note: Could not open files from r_app directory")
    message("Attempting to source from default directory instead...")
    tryCatch({
      source("parameters_project.R")
      paths <- setup_project_directories(project_dir)
      message("✓ Successfully sourced files from default directory")
    }, error = function(e) {
      stop("Failed to source required files from both 'r_app' and default directories.")
    })
  })
    data_source <- if (has_8b_data) {
      message("Auto-detected data source: merged_tif_8b (8-band optimized) - contains files")
      "merged_tif_8b"
    } else if (has_legacy_data) {
      message("Auto-detected data source: merged_tif (legacy 4-band) - contains files")
      "merged_tif"
    } else {
      message("Warning: No valid data source found (both folders empty or missing). Using default: merged_tif")
      "merged_tif"
    }
  }
  
  # Set global data_source for parameters_project.R
  assign("data_source", data_source, envir = .GlobalEnv)
  
  tryCatch({
    source("r_app/parameters_project.R")
    source("r_app/00_common_utils.R")
    source("r_app/40_mosaic_creation_utils.R")
    safe_log(paste("Successfully sourced files from 'r_app' directory."))
  }, error = function(e) {
    message("Note: Could not open files from r_app directory")
    message("Attempting to source from default directory instead...")
    tryCatch({
      source("parameters_project.R")
      paths <- setup_project_directories(project_dir)
      message("✓ Successfully sourced files from default directory")
    }, error = function(e) {
      stop("Failed to source required files from both 'r_app' and default directories.")
    })
  })
  
  # Use centralized paths (no need to manually construct or create dirs)
  merged_final <- paths$growth_model_interpolated_dir  # or merged_final_tif if needed
  daily_vrt <- paths$vrt_dir
  
  safe_log(paste("Using growth model/mosaic directory:", merged_final))
  safe_log(paste("Using daily VRT directory:", daily_vrt))
  
  # 4. Generate date range for processing
  # ---------------------------------
  dates <- date_list(end_date, offset)  
  safe_log(paste("Processing data for week", dates$week, "of", dates$year))
  
  # Create output filename
  # Only use custom filename if explicitly provided (not empty string)
  file_name_tif <- if (length(args) >= 4 && !is.na(args[4]) && nchar(args[4]) > 0) {
    as.character(args[4])
  } else {
    paste0("week_", sprintf("%02d", dates$week), "_", dates$year, ".tif")
  }
  
  safe_log(paste("Output will be saved as:", file_name_tif))
  
  # 5. Create weekly mosaics - route based on project tile detection
  # ---------------------------------------------------------------
  # The use_tile_mosaic flag is auto-detected by parameters_project.R
  # based on whether tiles exist in merged_final_tif/
  
  if (!exists("use_tile_mosaic")) {
    # Fallback detection if flag not set (shouldn't happen)
    merged_final_dir <- file.path(laravel_storage, "merged_final_tif")
    tile_detection <- detect_tile_structure_from_merged_final(merged_final_dir)
    use_tile_mosaic <- tile_detection$has_tiles
  }
  
  if (use_tile_mosaic) {
    # TILE-BASED APPROACH: Create per-tile weekly MAX mosaics
    # This is used for projects like Angata with large ROIs requiring spatial partitioning
    # Input data comes from merged_final_tif/{grid_size}/{DATE}/{DATE}_XX.tif (5-band tiles from script 20)
    tryCatch({
      safe_log("Starting per-tile mosaic creation (tile-based approach)...")
      
      # Detect grid size from merged_final_tif folder structure
      # Expected: merged_final_tif/5x5/ or merged_final_tif/10x10/ etc.
      merged_final_base <- file.path(laravel_storage, "merged_final_tif")
      grid_subfolders <- list.dirs(merged_final_base, full.names = FALSE, recursive = FALSE)
      # Look for grid size patterns like "5x5", "10x10", "20x20"
      grid_patterns <- grep("^\\d+x\\d+$", grid_subfolders, value = TRUE)
      
      if (length(grid_patterns) == 0) {
        stop("No grid size subfolder found in merged_final_tif/ (expected: 5x5, 10x10, etc.)")
      }
      
      grid_size <- grid_patterns[1]  # Use first grid size found
      safe_log(paste("Detected grid size:", grid_size))
      
      # Point to the grid-specific merged_final_tif directory
      merged_final_with_grid <- file.path(merged_final_base, grid_size)
      
      # Set output directory for per-tile mosaics, organized by grid size (from centralized paths)
      # Output: weekly_tile_max/{grid_size}/week_WW_YYYY_TT.tif
      tile_output_base <- file.path(paths$weekly_tile_max_dir, grid_size)
      # Note: no dir.create needed - paths$weekly_tile_max_dir already created by setup_project_directories()
      dir.create(tile_output_base, recursive = TRUE, showWarnings = FALSE)  # Create grid-size subfolder
      
      created_tile_files <- create_weekly_mosaic_from_tiles(
        dates = dates,
        merged_final_dir = merged_final_with_grid,
        tile_output_dir = tile_output_base,
        field_boundaries = field_boundaries
      )
      
      safe_log(paste("✓ Per-tile mosaic creation completed - created", 
                     length(created_tile_files), "tile files"))
    }, error = function(e) {
      safe_log(paste("ERROR in tile-based mosaic creation:", e$message), "ERROR")
      traceback()
      stop("Mosaic creation failed")
    })
    
  } else {
    # SINGLE-FILE APPROACH: Create single weekly mosaic file
    # This is used for legacy projects (ESA, Chemba, Aura) expecting single-file output
    tryCatch({
      safe_log("Starting single-file mosaic creation (backward-compatible approach)...")
      
      # Set output directory for single-file mosaics (from centralized paths)
      single_file_output_dir <- paths$weekly_mosaic_dir
      
      created_file <- create_weekly_mosaic(
        dates = dates,
        field_boundaries = field_boundaries,
        daily_vrt_dir = daily_vrt,
        merged_final_dir = merged_final,
        output_dir = single_file_output_dir,
        file_name_tif = file_name_tif,
        create_plots = FALSE
      )
      
      safe_log(paste("✓ Single-file mosaic creation completed:", created_file))
    }, error = function(e) {
      safe_log(paste("ERROR in single-file mosaic creation:", e$message), "ERROR")
      traceback()
      stop("Mosaic creation failed")
    })
  }
}

if (sys.nframe() == 0) {
  main()
}