#!/bin/bash
# ==============================================================================================
# ================================= CONFIGURATION LOADER =======================================
# ==============================================================================================
# Single entry point for all configuration sourcing across the ecosystem.
# Every script sources this file instead of sourcing master.conf files directly.
#
# ── HOW IT WORKS ──────────────────────────────────────────────────────────────────────────────
# 1. Detects OS platform → PLATFORM=unraid|truenas|unknown; exports SCRIPTS_DIR
# 2. Sources master.conf (shared config — hostnames, thresholds, toggles, profiles, job lists)
# 3. Auto-discovers and sources all host*.conf files in the same directory
#    Each host conf extends the shared profile arrays and adds host-specific credentials
# 4. Sources common.sh (shared functions — detect_hosts, logging, notifications etc.)
# 5. Sources Plugin/<platform>/adapter.sh (platform_*() functions for OS-specific ops)
#
# ── WHY THIS EXISTS ───────────────────────────────────────────────────────────────────────────
# Without this loader every script had to explicitly source each conf file:
#   source master.conf
#   source host1.conf
#   source host2.conf
#   source common.sh
#
# Adding a new server meant updating every script.
# With this loader — add host3.conf to the git repo and every server
# auto-discovers it on next git pull. Zero script changes required. Ever.
#
# ── ADDING A NEW SERVER ───────────────────────────────────────────────────────────────────────
# 1. Create Configurations/host3.conf following the same structure as HOST1/HOST2
# 2. Commit and push to git repo
# 3. All servers pull it automatically — no other changes needed
#
# ── USAGE IN SCRIPTS ──────────────────────────────────────────────────────────────────────────
# Replace the three source lines at the top of every script with:
#
#   SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
#   source "$SCRIPT_DIR/../load_config.sh"
#
# Scripts in subdirectories (Rsync/, Docker_Essentials/ etc.) use ../ to reach root.
# Scripts in root directory use ./ instead:
#
#   SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
#   source "$SCRIPT_DIR/load_config.sh"
#
# ── SPARSE CHECKOUT NOTE ──────────────────────────────────────────────────────────────────────
# Sparse checkout controls which host*.conf files each server receives.
# HOST1 only pulls Configurations/host1.conf — never HOST2's credentials.
# HOST2 only pulls Configurations/host2.conf — never HOST1's credentials.
# This loader sources whatever conf files ARE present — sparse checkout handles the rest.
# Both servers pull all non-credential conf files (Configurations/master.conf, common.sh, load_config.sh).
#
# ==============================================================================================

# ━━━ Locate config root ━━━
# load_config.sh always lives in the repo root.
# Scripts call it from subdirectories using ../ — resolve to the actual root.
    LOAD_CONFIG_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# ━━━ Platform detection ━━━
# PLATFORM drives the adapter layer — Plugin/<platform>/adapter.sh
# Each platform adapter provides the same function API; scripts stay OS-agnostic.
    if   [[ -f /etc/unraid-version ]]; then  PLATFORM="unraid"
    elif [[ -f /etc/truenas ]];        then  PLATFORM="truenas"
    else                                     PLATFORM="unknown"
    fi
    export PLATFORM SCRIPTS_DIR="$LOAD_CONFIG_DIR"

# ━━━ Source shared config ━━━
# master.conf must be sourced first — it declares the shared PROFILE_* arrays
# that Host confs extend. Sourcing host confs before master.conf would fail.
    if [[ ! -f "$LOAD_CONFIG_DIR/Configurations/master.conf" ]]; then
        echo "[FATAL] master.conf not found at $LOAD_CONFIG_DIR/Configurations/master.conf" >&2
        echo "[FATAL] Check TARGET_DIR and git pull status" >&2
        exit 1
    fi
    source "$LOAD_CONFIG_DIR/Configurations/master.conf"

# ━━━ Auto-discover and source all host*.conf files ━━━
# Sorted for consistent load order — HOST1 before HOST2 before HOST3 etc.
# Each host conf extends the shared PROFILE_* arrays and adds host-specific vars.
# Missing files are silently skipped — sparse checkout intentionally withholds some.
# At least one host conf must be present or the ecosystem has no identity to work with.
    _host_confs_loaded=0
    declare -A _disk_conf_basenames=()

    # Use a sorted array glob — avoids word-splitting on paths with spaces
    while IFS= read -r _conf; do
        [[ -f "$_conf" ]] || continue
        source "$_conf"
        (( _host_confs_loaded++ ))
        _disk_conf_basenames["$(basename "$_conf")"]=1
        [[ "${ENABLE_LOGGING:-false}" == "true" ]] && \
            echo "[LOG] Loaded host config: $(basename "$_conf")" >&2
    done < <(printf '%s\n' "$LOAD_CONFIG_DIR/Configurations"/host*.conf 2>/dev/null | sort)

    if [[ "$_host_confs_loaded" -eq 0 ]]; then
        echo "[FATAL] No host*.conf files found in $LOAD_CONFIG_DIR" >&2
        echo "[FATAL] At least one host conf required — check git pull and sparse checkout" >&2
        exit 1
    fi

# ━━━ Source partner confs from /tmp cache ━━━
# conf_sync.sh pulls partner host*.conf files into /tmp/.vv/config/cached/.confs/
# on array start and after any conf save. Sourcing them here makes partner vars
# (HOST2_*, HOST3_*, …) available without committing credentials to the git repo
# or violating sparse checkout — partner confs live in RAM only, cleared on reboot.
# Confs already loaded from disk are skipped — disk copy is authoritative.
    _VV_CONF_CACHE="/tmp/.vv/config/cached/.confs"
    if [[ -d "$_VV_CONF_CACHE" ]]; then
        while IFS= read -r _conf; do
            [[ -f "$_conf" ]] || continue
            _conf_base="$(basename "$_conf")"
            # Skip if already sourced from disk
            [[ -n "${_disk_conf_basenames[$_conf_base]:-}" ]] && continue
            source "$_conf"
            [[ "${ENABLE_LOGGING:-false}" == "true" ]] && \
                echo "[LOG] Loaded cached partner config: $_conf_base" >&2
        done < <(printf '%s\n' "$_VV_CONF_CACHE"/host*.conf 2>/dev/null | sort)
    fi
    unset _VV_CONF_CACHE _conf_base _disk_conf_basenames

# ━━━ Source shared functions ━━━
# common.sh sourced last — it calls detect_hosts() which needs HOST* vars to be set.
    if [[ ! -f "$LOAD_CONFIG_DIR/common.sh" ]]; then
        echo "[FATAL] common.sh not found at $LOAD_CONFIG_DIR/common.sh" >&2
        exit 1
    fi
    source "$LOAD_CONFIG_DIR/common.sh"

# ━━━ Source platform adapter ━━━
# Provides platform_*() functions used by common.sh and scripts.
# Guard lets the ecosystem run before Plugin/<platform>/adapter.sh exists.
    _adapter="$LOAD_CONFIG_DIR/Plugin/$PLATFORM/adapter.sh"
    [[ -f "$_adapter" ]] && source "$_adapter"

# ━━━ Derived path constants ━━━
# Centralised here so every script that sources load_config.sh has them without
# re-deriving from SCRIPTS_DIR or hardcoding /var/log or /tmp paths inline.
    CONF_DIR="${SCRIPTS_DIR}/Configurations"
    LOG_DIR="/var/log/varaverk"
    VV_CACHE_DIR="/tmp/vv_cache"
    export CONF_DIR LOG_DIR VV_CACHE_DIR

# ━━━ Cleanup ━━━
    unset _conf _host_confs_loaded _adapter LOAD_CONFIG_DIR