#!/bin/bash

# Pretty display for GitHub PR checks using gum
# Usage: ./gh-pr-checks-pretty.sh <PR_NUMBER> [--watch]

set -euo pipefail

# Parse arguments
WATCH_MODE=false
PR_NUMBER=""

while [[ $# -gt 0 ]]; do
    case $1 in
        --watch|-w)
            WATCH_MODE=true
            shift
            ;;
        *)
            PR_NUMBER=$1
            shift
            ;;
    esac
done

# Check if PR number is provided
if [ -z "$PR_NUMBER" ]; then
    echo "Usage: $0 <PR_NUMBER> [--watch]"
    exit 1
fi

# Check if gum is installed
if ! command -v gum &> /dev/null; then
    echo "Error: gum is not installed. Install it from https://github.com/charmbracelet/gum"
    exit 1
fi

# Check if gh is installed
if ! command -v gh &> /dev/null; then
    echo "Error: gh (GitHub CLI) is not installed."
    exit 1
fi

# Function to display checks
display_checks() {
    # Get PR details including reviews, comments, and state
    PR_INFO=$(gh pr view "$PR_NUMBER" --json number,title,url,state,isDraft,reviews,comments)
    PR_TITLE=$(echo "$PR_INFO" | jq -r '.title')
    PR_URL=$(echo "$PR_INFO" | jq -r '.url')
    PR_STATE=$(echo "$PR_INFO" | jq -r '.state')
    PR_DRAFT=$(echo "$PR_INFO" | jq -r '.isDraft')

    # Count comments
    COMMENT_COUNT=$(echo "$PR_INFO" | jq '.comments | length')

    # Get approval status
    APPROVED_COUNT=$(echo "$PR_INFO" | jq '[.reviews[] | select(.state == "APPROVED")] | length')
    CHANGES_REQUESTED=$(echo "$PR_INFO" | jq '[.reviews[] | select(.state == "CHANGES_REQUESTED")] | length')

    # Determine PR status string
    if [ "$PR_DRAFT" = "true" ]; then
        PR_STATUS="Draft"
        STATUS_COLOR="8"  # Gray
    elif [ "$PR_STATE" = "MERGED" ]; then
        PR_STATUS="Merged"
        STATUS_COLOR="13"  # Purple
    elif [ "$PR_STATE" = "CLOSED" ]; then
        PR_STATUS="Closed"
        STATUS_COLOR="9"  # Red
    else
        PR_STATUS="Open"
        STATUS_COLOR="10"  # Green
    fi

    # Determine approval string
    if [ "$CHANGES_REQUESTED" -gt 0 ]; then
        APPROVAL_STATUS="Changes requested"
        APPROVAL_COLOR="9"  # Red
    elif [ "$APPROVED_COUNT" -gt 0 ]; then
        APPROVAL_STATUS="✓ Approved ($APPROVED_COUNT)"
        APPROVAL_COLOR="10"  # Green
    else
        APPROVAL_STATUS="No reviews"
        APPROVAL_COLOR="8"  # Gray
    fi

    # Get checks with full details
    CHECKS_JSON=$(gh pr checks "$PR_NUMBER" --json bucket,name,link,completedAt,description,state)

    # Count all checks
    TOTAL_ALL=$(echo "$CHECKS_JSON" | jq '. | length')
    SUCCESSFUL_ALL=$(echo "$CHECKS_JSON" | jq '[.[] | select(.state == "SUCCESS")] | length')
    FAILING_ALL=$(echo "$CHECKS_JSON" | jq '[.[] | select(.state == "FAILURE")] | length')
    PENDING_ALL=$(echo "$CHECKS_JSON" | jq '[.[] | select(.state == "PENDING" or .state == "IN_PROGRESS")] | length')

    # Filter checks: only include Terraform results, failures, or ongoing checks
    FILTERED_JSON=$(echo "$CHECKS_JSON" | jq '[.[] | select(
        (.description | contains("Run not triggered") | not) and
        (
            (.description | contains("Terraform plan:")) or
            (.state == "FAILURE") or
            (.state == "PENDING") or
            (.state == "IN_PROGRESS")
        )
    )]')

    # Count filtered checks
    TOTAL=$(echo "$FILTERED_JSON" | jq '. | length')
    HIDDEN=$((SUCCESSFUL_ALL - TOTAL))

    # Clear screen in watch mode
    if [ "$WATCH_MODE" = true ]; then
        clear
    fi

    # Display header
    gum style \
        --border double \
        --border-foreground 212 \
        --padding "1 2" \
        --margin "1 0" \
        --align center \
        "#$PR_NUMBER | $PR_TITLE" "$PR_URL"

    # Display PR status, approval, and comments
    echo ""
    gum style --foreground "$STATUS_COLOR" --bold "Status: $PR_STATUS" | tr '\n' ' '
    echo -n " | "
    gum style --foreground "$APPROVAL_COLOR" "Reviews: $APPROVAL_STATUS" | tr '\n' ' '
    echo -n " | "
    gum style --foreground 12 "Comments: $COMMENT_COUNT"

    # Display summary statistics
    echo ""
    if [ "$TOTAL" -eq 0 ]; then
        gum style --foreground 8 "Total: $TOTAL_ALL | Success: $SUCCESSFUL_ALL | Failed: $FAILING_ALL | Pending: $PENDING_ALL"
        echo ""
        gum style \
            --foreground 10 \
            --bold \
            "✓ All checks passed"

        if [ "$WATCH_MODE" = false ]; then
            exit 0
        else
            return 0
        fi
    else
        gum style --foreground 8 "Total: $TOTAL_ALL | Success: $SUCCESSFUL_ALL ($HIDDEN hidden) | Failed: $FAILING_ALL | Pending: $PENDING_ALL"
    fi

    echo ""

    # Prepare table data
    TABLE_DATA=$(echo "$FILTERED_JSON" | jq -r '
        ["  STATUS", "NAME", "DESCRIPTION", "URL"],
        ["  ──────", "────", "───────────", "───"],
        (.[] | [
            "  " + (if .state == "SUCCESS" then "✓"
             elif .state == "FAILURE" then "✗"
             elif .state == "PENDING" or .state == "IN_PROGRESS" then "⏳"
             else "○" end),
            # Shorten name - extract workspace from Terraform Cloud checks
            (if .name | startswith("Terraform Cloud/") then
                "TF - " + (.name | split("/") | last)
             else
                .name
             end),
            # Format description - compact Terraform plan output
            (if .description and (.description | contains("Terraform plan:")) then
                (.description |
                    gsub("Terraform plan: "; "") |
                    gsub(" to add"; "") |
                    gsub(" to change"; "") |
                    gsub(" to destroy\\."; "") |
                    gsub(", "; " ") |
                    split(" ") |
                    "🟢+" + .[0] + " 🛠~" + .[1] + " 🗑-" + .[2])
             else
                (.description // "No description" |
                    if (. | length) > 50 then .[0:47] + "..." else . end)
             end),
            # Full URL
            (.link // "")
        ]) | @tsv
    ' | column -t -s $'\t')

    # Display table with gum
    echo "$TABLE_DATA" | gum format

    # Show timestamp in watch mode
    if [ "$WATCH_MODE" = true ]; then
        echo ""
        gum style --foreground 8 --italic "Last updated: $(date '+%Y-%m-%d %H:%M:%S')"
    fi
}

# Run in watch mode or single run
if [ "$WATCH_MODE" = true ]; then
    # Trap Ctrl+C to exit gracefully
    trap 'echo ""; echo "Watch mode stopped."; exit 0' INT

    while true; do
        display_checks

        # Check if all checks are complete
        CHECKS_JSON=$(gh pr checks "$PR_NUMBER" --json state)
        PENDING_COUNT=$(echo "$CHECKS_JSON" | jq '[.[] | select(.state == "PENDING" or .state == "IN_PROGRESS")] | length')

        if [ "$PENDING_COUNT" -eq 0 ]; then
            echo ""
            gum style --foreground 10 --bold "All checks complete!"
            break
        fi

        sleep 10
    done
else
    display_checks
fi