#!/usr/bin/env bash
# Apply pending SQL migrations to one or both SQLite databases.
# Usage:
#   scripts/migrate.sh              # migrates both test.db and posterg.db
#   scripts/migrate.sh test         # migrates storage/test.db only
#   scripts/migrate.sh prod         # migrates storage/posterg.db only

set -euo pipefail

REPO_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
APP_DIR="$REPO_ROOT/app"
MIGRATIONS_DIR="$APP_DIR/storage/migrations"
TEST_DB="$APP_DIR/storage/test.db"
PROD_DB="$APP_DIR/storage/posterg.db"

# ---------------------------------------------------------------------------
# Check whether a migration's effects are already present in the DB so that
# legacy databases (created before the migrations table existed) can be
# bootstrapped correctly without re-running non-idempotent SQL.
# ---------------------------------------------------------------------------
already_applied_structurally() {
    local db="$1"
    local name="$2"

    case "$name" in
        001_rename_keywords_to_tags.sql)
            # Effect: table 'tags' and 'thesis_tags' exist
            count=$(sqlite3 "$db" "SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name IN ('tags','thesis_tags');")
            [ "$count" -eq 2 ]
            ;;
        002_add_visibility.sql)
            # Effect: access_types seed rows (always safe to re-run with OR IGNORE, but mark done if rows exist)
            count=$(sqlite3 "$db" "SELECT COUNT(*) FROM access_types WHERE id IN (1,2,3);" 2>/dev/null || echo 0)
            [ "$count" -eq 3 ]
            ;;
        003_seed_license_types.sql)
            # Effect: at least one row in license_types
            count=$(sqlite3 "$db" "SELECT COUNT(*) FROM license_types;" 2>/dev/null || echo 0)
            [ "$count" -gt 0 ]
            ;;
        004_jury_roles.sql)
            # Effect: 'role' column on thesis_supervisors
            count=$(sqlite3 "$db" "SELECT COUNT(*) FROM pragma_table_info('thesis_supervisors') WHERE name='role';")
            [ "$count" -eq 1 ]
            ;;
        005_add_banner.sql)
            # Effect: 'banner_path' column on theses
            count=$(sqlite3 "$db" "SELECT COUNT(*) FROM pragma_table_info('theses') WHERE name='banner_path';")
            [ "$count" -eq 1 ]
            ;;
        006_add_composite_index.sql)
            # Effect: index idx_theses_pub_year exists (CREATE INDEX IF NOT EXISTS — safe to re-run anyway)
            count=$(sqlite3 "$db" "SELECT COUNT(*) FROM sqlite_master WHERE type='index' AND name='idx_theses_pub_year';")
            [ "$count" -eq 1 ]
            ;;
        008_formulaire_settings.sql)
            # Effect: site_settings table exists + show_contact column on authors
            tbl=$(sqlite3 "$db" "SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name='site_settings';")
            col=$(sqlite3 "$db" "SELECT COUNT(*) FROM pragma_table_info('authors') WHERE name='show_contact';")
            [ "$tbl" -eq 1 ] && [ "$col" -eq 1 ]
            ;;
        012_smtp_settings.sql)
            tbl=$(sqlite3 "$db" "SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name='smtp_settings';")
            [ "$tbl" -eq 1 ]
            ;;
        013_admin_password.sql)
            # Effect: admin_password_hash key exists in site_settings (INSERT OR IGNORE — safe to re-run)
            count=$(sqlite3 "$db" "SELECT COUNT(*) FROM site_settings WHERE key='admin_password_hash';")
            [ "$count" -eq 1 ]
            ;;
        *)
            # Unknown migration — assume not applied
            return 1
            ;;
    esac
}

migrate_db() {
    local db="$1"
    local label="$2"

    # Auto-create from schema only when the file is absent or truly empty (no tables)
    local table_count
    table_count=$(sqlite3 "$db" "SELECT COUNT(*) FROM sqlite_master WHERE type='table';" 2>/dev/null || echo 0)
    if [ "$table_count" -eq 0 ]; then
        echo "  [$label] initialising from schema…"
        sqlite3 "$db" < "$APP_DIR/storage/schema.sql"
        echo "  [$label] schema applied."
    fi

    # Ensure tracking table exists
    sqlite3 "$db" "CREATE TABLE IF NOT EXISTS schema_migrations (
        name TEXT PRIMARY KEY,
        applied_at TEXT NOT NULL DEFAULT (datetime('now'))
    );"

    local applied=0
    local seeded=0
    local skipped=0

    for migration in "$MIGRATIONS_DIR"/*.sql; do
        name="$(basename "$migration")"
        already=$(sqlite3 "$db" "SELECT COUNT(*) FROM schema_migrations WHERE name='$name';")

        if [ "$already" -eq 1 ]; then
            skipped=$((skipped + 1))
            continue
        fi

        # Not in tracking table — check if it was already applied before we started tracking
        if already_applied_structurally "$db" "$name"; then
            sqlite3 "$db" "INSERT OR IGNORE INTO schema_migrations (name) VALUES ('$name');"
            seeded=$((seeded + 1))
            echo "  [$label] seeded  $name (already applied)"
            continue
        fi

        echo "  [$label] applying $name …"
        if sqlite3 "$db" < "$migration"; then
            sqlite3 "$db" "INSERT OR IGNORE INTO schema_migrations (name) VALUES ('$name');"
            applied=$((applied + 1))
        else
            echo "  [$label] ERROR applying $name — aborting" >&2
            exit 1
        fi
    done

    echo "  [$label] done — $applied applied, $seeded seeded, $skipped already up-to-date"
}

TARGET="${1:-both}"

case "$TARGET" in
    test)  migrate_db "$TEST_DB"  "test.db"    ;;
    prod)  migrate_db "$PROD_DB"  "posterg.db" ;;
    both)
        migrate_db "$TEST_DB"  "test.db"
        migrate_db "$PROD_DB"  "posterg.db"
        ;;
    *)
        echo "Usage: $0 [test|prod|both]" >&2
        exit 1
        ;;
esac