#!/bin/sh
set -eu

# 1️⃣  Presets
PRESETS=" 0.15 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00"

# Per-window saved-proportion directory
PROPORTION_DIR="${XDG_RUNTIME_DIR:-/tmp}/mango-resize"

# 2️⃣  Helper: abort with a clear message if a required binary is missing
need_cmd() {
    command -v "$1" >/dev/null 2>&1 || {
        printf "❌ Required command '%s' not found in PATH. Install it first.\n" "$1" >&2
        exit 127
    }
}
need_cmd mmsg
need_cmd jq
need_cmd awk
need_cmd wc
need_cmd sed

# 3️⃣  Get the *currently focused* client.
client_json=$(mmsg get focusing-client || true)

# 3a️⃣ Extract the window's unique id (used as the per-window state key)
win_id=$(printf '%s' "$client_json" | jq -r '.id // empty' || true)
if [ -z "$win_id" ]; then
    printf "⚠️  Could not determine window id – aborting.\n" >&2
    exit 1
fi

# Per-window state file
PROPORTION_FILE="$PROPORTION_DIR/$win_id"

# 3b️⃣  Extract current client width
current=$(printf '%s' "$client_json" | jq -r '.width // empty' || true)

if [ -z "$current" ]; then
    printf "⚠️ No focusing client reported – using monitor width as current size.\n"
    current=$(mmsg get all-monitors | jq -r '
        if type == "array" then
            (map(select(.active == true))[0].width)
        else
            (.monitors | map(select(.active == true))[0].width)
        end
    ' || true)
fi

# 4️⃣  Get the *usable* work‑area width
usable_width=$(mmsg get workarea 2>/dev/null || true)
if [ -n "$usable_width" ]; then
    usable_width=$(printf '%s' "$usable_width" | jq -r '.width // empty')
fi
if [ -z "$usable_width" ]; then
    usable_width=$(mmsg get all-monitors | jq -r '
        if type == "array" then
            (map(select(.active == true))[0].width)
        else
            (.monitors | map(select(.active == true))[0].width)
        end
    ')
fi

# 5️⃣  Compute the proportion
approx=$(awk -v cw="$current" -v uw="$usable_width" '
    BEGIN {
        if (uw <= 0) { print "0.50"; exit }
        printf "%.4f\n", cw / uw
    }')

# 6️⃣  Find the nearest preset index
nearest_index=$(awk -v target="$approx" '
    BEGIN {
        split("'"$PRESETS"'", a, " ");
        best_i = 1;
        best_d = 999;
        for (i = 1; i <= length(a); i++) {
            d = a[i] - target;
            if (d < 0) d = -d;
            if (d < best_d) {
                best_d = d;
                best_i = i;
            }
        }
        print best_i;
    }')

# 7️⃣  Apply the direction argument
case "${1:-}" in
    up)   new_index=$((nearest_index + 1)) ;;
    down) new_index=$((nearest_index - 1)) ;;
    fullscreen)
    # Check if currently fullscreen (approx >= 0.95 → treat as fullscreen)
    is_fullscreen=$(awk -v a="$approx" 'BEGIN { print (a >= 0.95) ? "1" : "0" }')
    if [ "$is_fullscreen" = "1" ]; then
        # Currently fullscreen → restore this window's saved proportion
        if [ -f "$PROPORTION_FILE" ]; then
            saved=$(cat "$PROPORTION_FILE")
            mmsg dispatch "set_proportion,$saved"
            printf "✅ [win %s] Restored proportion to %s (fullscreen toggle off)\n" "$win_id" "$saved"
            rm -f "$PROPORTION_FILE"
        else
            printf "⚠️  [win %s] No saved proportion – defaulting to 0.50\n" "$win_id" >&2
            mmsg dispatch "set_proportion,0.50"
        fi
    else
        # Not fullscreen → save this window's proportion & go fullscreen
        saved=$(printf '%s\n' $PRESETS | sed -n "${nearest_index}p")
        mkdir -p "$PROPORTION_DIR"
        printf '%s' "$saved" > "$PROPORTION_FILE"
        mmsg dispatch "set_proportion,1.00"
        printf "✅ [win %s] Saved proportion %s, set to 1.00 (fullscreen toggle on)\n" "$win_id" "$saved"
    fi
    exit 0
    ;;
    *)    printf "❌ Usage: %s [up|down|fullscreen]\n" "$0" >&2; exit 1 ;;
esac

# 8️⃣  Clamp
count=$(printf '%s\n' $PRESETS | wc -l)
if [ "$new_index" -lt 1 ];   then new_index=1;   fi
if [ "$new_index" -gt "$count" ]; then new_index=$count; fi

# 9️⃣  Resolve the new preset value
new_value=$(printf '%s\n' $PRESETS | sed -n "${new_index}p")

# 🔟  Dispatch
mmsg dispatch "set_proportion,$new_value"
printf "✅ Set proportion to %s (preset %s of %s)\n" "$new_value" "$new_index" "$count"