# 09_CALCULATE_KPIS.R
# ===================
# This script calculates 6 Key Performance Indicators (KPIs) for sugarcane monitoring:
# 1. Field Uniformity Summary
# 2. Farm-wide Area Change Summary
# 3. TCH Forecasted
# 4. Growth Decline Index
# 5. Weed Presence Score
# 6. Gap Filling Score (placeholder)
#
# Usage: Rscript 09_calculate_kpis.R [end_date] [offset] [project_dir]
#   - end_date: End date for KPI calculation (YYYY-MM-DD format), default: today
#   - offset: Number of days to look back (not currently used for KPIs, but for consistency)
#   - project_dir: Project directory name (e.g., "aura", "esa")

# 1. Load required libraries
# -------------------------
suppressPackageStartupMessages({
  library(here)
  library(sf)
  library(terra)
  library(dplyr)
  library(tidyr)
  library(lubridate)
  library(readr)
  library(caret)
  library(CAST)
  library(randomForest)
})

# 2. Main function
# --------------
main <- function() {
  # Process command line arguments
  args <- commandArgs(trailingOnly = TRUE)
  
  # Process end_date argument
  if (length(args) >= 1 && !is.na(args[1])) {
    end_date <- as.Date(args[1])
    if (is.na(end_date)) {
      warning("Invalid end_date provided. Using default (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 {
    end_date <- Sys.Date()
  }
  
  # Process offset argument (for consistency with other scripts, not currently used)
  if (length(args) >= 2 && !is.na(args[2])) {
    offset <- as.numeric(args[2])
    if (is.na(offset) || offset <= 0) {
      warning("Invalid offset provided. Using default (7 days).")
      offset <- 7
    }
  } else if (exists("offset", envir = .GlobalEnv)) {
    offset <- get("offset", envir = .GlobalEnv)
  } else {
    offset <- 7
  }
  
  # Process project_dir argument
  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 {
    project_dir <- "esa"  # Default project
  }
  
  # Make project_dir available globally so parameters_project.R can use it
  assign("project_dir", project_dir, envir = .GlobalEnv)
  
  # 3. Load utility functions and project configuration
  # --------------------------------------------------
  
  tryCatch({
    source(here("r_app", "crop_messaging_utils.R"))
  }, error = function(e) {
    stop("Error loading crop_messaging_utils.R: ", e$message)
  })
  
  tryCatch({
    source(here("r_app", "kpi_utils.R"))
  }, error = function(e) {
    stop("Error loading kpi_utils.R: ", e$message)
  })
  
  # Load project parameters (this sets up all directory paths and field boundaries)
  tryCatch({
    source(here("r_app", "parameters_project.R"))
  }, error = function(e) {
    stop("Error loading parameters_project.R: ", e$message)
  })
  
  # Load growth model utils if available (for yield prediction)
  tryCatch({
    source(here("r_app", "30_growth_model_utils.R"))
  }, error = function(e) {
    warning("30_growth_model_utils.R not found, yield prediction KPI will use placeholder data")
  })
  
  # Check if required variables exist
  if (!exists("project_dir")) {
    stop("project_dir must be set before running this script")
  }
  
  if (!exists("field_boundaries_sf") || is.null(field_boundaries_sf)) {
    stop("Field boundaries not loaded. Check parameters_project.R initialization.")
  }
  
  # 4. Calculate all KPIs
  # -------------------
  output_dir <- file.path(reports_dir, "kpis")
  
  kpi_results <- calculate_all_kpis(
    report_date = end_date,
    output_dir = output_dir,
    field_boundaries_sf = field_boundaries_sf,
    harvesting_data = harvesting_data,
    cumulative_CI_vals_dir = cumulative_CI_vals_dir,
    weekly_CI_mosaic = weekly_CI_mosaic,
    reports_dir = reports_dir,
    project_dir = project_dir
  )
  
  # 5. Print summary
  # --------------
  cat("\n=== KPI CALCULATION SUMMARY ===\n")
  cat("Report Date:", as.character(kpi_results$metadata$report_date), "\n")
  cat("Current Week:", kpi_results$metadata$current_week, "\n")
  cat("Previous Week:", kpi_results$metadata$previous_week, "\n")
  cat("Total Fields Analyzed:", kpi_results$metadata$total_fields, "\n")
  cat("Calculation Time:", as.character(kpi_results$metadata$calculation_time), "\n")
  
  cat("\nField Uniformity Summary:\n")
  print(kpi_results$field_uniformity_summary)
  
  cat("\nArea Change Summary:\n")
  print(kpi_results$area_change)
  
  cat("\nTCH Forecasted:\n")
  print(kpi_results$tch_forecasted)
  
  cat("\nGrowth Decline Index:\n")
  print(kpi_results$growth_decline)
  
  cat("\nWeed Presence Score:\n")
  print(kpi_results$weed_presence)
  
  cat("\nGap Filling Score:\n")
  print(kpi_results$gap_filling)
  
  cat("\n=== KPI CALCULATION COMPLETED ===\n")
}

# 6. Script execution
# -----------------
if (sys.nframe() == 0) {
  main()
}