import datetime

from pdpyras import APISession

from lib.common.report import TAB
from lib.common.resources.users import match_user
from lib.grafana.service_model_client import ServiceModelClient
from lib.oncall.api_client import OnCallAPIClient
from lib.pagerduty.config import (
    EXPERIMENTAL_MIGRATE_EVENT_RULES,
    MIGRATE_USERS,
    MODE,
    MODE_PLAN,
    PAGERDUTY_API_TOKEN,
    PAGERDUTY_FILTER_USERS,
    PAGERDUTY_MIGRATE_SERVICES,
)
from lib.pagerduty.report import (
    escalation_policy_report,
    format_escalation_policy,
    format_integration,
    format_ruleset,
    format_schedule,
    format_user,
    integration_report,
    ruleset_report,
    schedule_report,
    services_report,
    user_report,
)
from lib.pagerduty.resources.escalation_policies import (
    filter_escalation_policies,
    match_escalation_policy,
    match_escalation_policy_for_integration,
    migrate_escalation_policy,
)
from lib.pagerduty.resources.integrations import (
    filter_integrations,
    match_integration,
    match_integration_type,
    migrate_integration,
)
from lib.pagerduty.resources.notification_rules import migrate_notification_rules
from lib.pagerduty.resources.rulesets import match_ruleset, migrate_ruleset
from lib.pagerduty.resources.schedules import (
    filter_schedules,
    match_schedule,
    migrate_schedule,
)
from lib.pagerduty.resources.services import (
    BusinessService,
    TechnicalService,
    filter_services,
    get_all_business_services_with_metadata,
    get_all_technical_services_with_metadata,
    migrate_all_services,
)
from lib.pagerduty.resources.users import (
    filter_users,
    match_users_and_schedules_for_escalation_policy,
    match_users_for_schedule,
)


def migrate() -> None:
    # Set up API sessions and timeout
    session = APISession(PAGERDUTY_API_TOKEN)
    session.timeout = 20

    # Use a flag to track how many resources were eligible for migration in the final report
    filtered_resources_summary = {
        "schedules": 0,
        "escalation_policies": 0,
        "integrations": 0,
    }

    # Process users only if MIGRATE_USERS is true
    users = []
    oncall_users = []
    user_id_map = {}

    if MIGRATE_USERS:
        print("▶ Fetching users...")
        users = session.list_all("users", params={"include[]": "notification_rules"})
        oncall_users = OnCallAPIClient.list_users_with_notification_rules()

        # Apply filtering to users if specified
        if PAGERDUTY_FILTER_USERS:
            print("▶ Filtering users based on PAGERDUTY_FILTER_USERS...")
            users = filter_users(users)

        # Match users with Grafana OnCall users
        for user in users:
            match_user(user, oncall_users)

        # Create a mapping from PagerDuty user IDs to Grafana OnCall user IDs
        user_id_map = {
            u["id"]: u["oncall_user"]["id"] if u["oncall_user"] else None for u in users
        }
    else:
        print("▶ Skipping user fetching and migration as MIGRATE_USERS is false...")

    print("▶ Fetching schedules...")
    # Fetch schedules from PagerDuty
    schedules = session.list_all(
        "schedules",
        params={"include[]": ["schedule_layers", "teams"], "time_zone": "UTC"},
    )

    # Apply filters to schedules
    schedules = filter_schedules(schedules)
    filtered_resources_summary["schedules"] = len(schedules)
    print(f"Found {len(schedules)} schedules after filtering")

    # Fetch overrides from PagerDuty
    since = datetime.datetime.now(datetime.timezone.utc)
    until = since + datetime.timedelta(
        days=365
    )  # fetch overrides up to 1 year from now
    for schedule in schedules:
        response = session.jget(
            f"schedules/{schedule['id']}/overrides",
            params={"since": since.isoformat(), "until": until.isoformat()},
        )
        schedule["overrides"] = response["overrides"]

    # Fetch schedules from OnCall
    oncall_schedules = OnCallAPIClient.list_all("schedules")

    print("▶ Fetching escalation policies...")
    escalation_policies = session.list_all(
        "escalation_policies", params={"include[]": "teams"}
    )

    # Apply filters to escalation policies
    escalation_policies = filter_escalation_policies(escalation_policies)
    filtered_resources_summary["escalation_policies"] = len(escalation_policies)
    print(f"Found {len(escalation_policies)} escalation policies after filtering")

    oncall_escalation_chains = OnCallAPIClient.list_all("escalation_chains")

    print("▶ Fetching integrations...")
    services = session.list_all(
        "services", params={"include[]": ["integrations", "teams"]}
    )
    vendors = session.list_all("vendors")

    integrations = []
    for service in services:
        service_integrations = service.pop("integrations")
        for integration in service_integrations:
            integration["service"] = service
            integrations.append(integration)

    # Apply filters to integrations
    integrations = filter_integrations(integrations)
    filtered_resources_summary["integrations"] = len(integrations)
    print(f"Found {len(integrations)} integrations after filtering")

    oncall_integrations = OnCallAPIClient.list_all("integrations")

    rulesets = None
    if EXPERIMENTAL_MIGRATE_EVENT_RULES:
        print("▶ Fetching event rules (global rulesets)...")
        rulesets = session.list_all("rulesets")
        for ruleset in rulesets:
            rules = session.list_all(f"rulesets/{ruleset['id']}/rules")
            ruleset["rules"] = rules

    # Match resources if we have users
    for schedule in schedules:
        match_schedule(schedule, oncall_schedules, user_id_map)
        if MIGRATE_USERS:
            match_users_for_schedule(schedule, users)
        else:
            # When not migrating users, mark schedule as having no unmatched users
            schedule["unmatched_users"] = []
            schedule["migration_errors"] = []

    for policy in escalation_policies:
        match_escalation_policy(policy, oncall_escalation_chains)
        if MIGRATE_USERS:
            match_users_and_schedules_for_escalation_policy(policy, users, schedules)
        else:
            # When not migrating users, mark policy as having no unmatched users
            policy["unmatched_users"] = []
            policy["flawed_schedules"] = []

    for integration in integrations:
        match_integration(integration, oncall_integrations)
        match_integration_type(integration, vendors)
        match_escalation_policy_for_integration(integration, escalation_policies)

    if rulesets is not None:
        for ruleset in rulesets:
            match_ruleset(
                ruleset,
                oncall_integrations,
                escalation_policies,
                services,
                integrations,
            )

    if PAGERDUTY_MIGRATE_SERVICES:
        client = ServiceModelClient()
        # Get all services
        all_technical_services = get_all_technical_services_with_metadata(session)
        technical_service_map = {
            service.id: service for service in all_technical_services
        }
        all_business_services = get_all_business_services_with_metadata(
            session, technical_service_map
        )

        # Apply filters to services
        filtered_technical_data = filter_services(
            [service.raw_data for service in all_technical_services]
        )
        filtered_business_data = filter_services(
            [service.raw_data for service in all_business_services]
        )

        # Convert filtered data back to service objects
        technical_services = [
            TechnicalService(service) for service in filtered_technical_data
        ]
        business_services = [
            BusinessService(service) for service in filtered_business_data
        ]

    # Print filtering and matching summary
    print("\n▶ Migration summary after filtering and matching:")
    if MIGRATE_USERS:
        print(
            f"Users: {sum(1 for u in users if u.get('oncall_user'))} matched of {len(users)} total"
        )
    print(
        f"Schedules: {sum(1 for s in schedules if not s.get('unmatched_users') and not s.get('migration_errors'))} eligible of {filtered_resources_summary['schedules']} filtered"
    )
    print(
        f"Escalation policies: {sum(1 for p in escalation_policies if not p.get('unmatched_users') and not p.get('flawed_schedules'))} eligible of {filtered_resources_summary['escalation_policies']} filtered"
    )
    print(
        f"Integrations: {sum(1 for i in integrations if i.get('oncall_type') and not i.get('is_escalation_policy_flawed'))} eligible of {filtered_resources_summary['integrations']} filtered\n"
    )

    if MODE == MODE_PLAN:
        if MIGRATE_USERS:
            print(user_report(users), end="\n\n")
        print(schedule_report(schedules), end="\n\n")
        print(escalation_policy_report(escalation_policies), end="\n\n")
        print(integration_report(integrations), end="\n\n")

        if rulesets is not None:
            print(ruleset_report(rulesets), end="\n\n")

        if PAGERDUTY_MIGRATE_SERVICES:
            print(
                services_report(
                    all_technical_services,
                    all_business_services,
                    technical_services,
                    business_services,
                ),
                end="\n\n",
            )

            return

        return

    if MIGRATE_USERS:
        print("▶ Migrating user notification rules...")
        for user in users:
            if user["oncall_user"]:
                migrate_notification_rules(user)
                print(TAB + format_user(user))
    else:
        print(
            "▶ Skipping migrating user notification rules as MIGRATE_USERS is false..."
        )

    print("▶ Migrating schedules...")
    for schedule in schedules:
        if not schedule["unmatched_users"] and not schedule["migration_errors"]:
            migrate_schedule(schedule, user_id_map)
            print(TAB + format_schedule(schedule))

    print("▶ Migrating escalation policies...")
    for policy in escalation_policies:
        if not policy["unmatched_users"] and not policy["flawed_schedules"]:
            migrate_escalation_policy(policy, users, schedules)
            print(TAB + format_escalation_policy(policy))

    print("▶ Migrating integrations...")
    for integration in integrations:
        if (
            integration["oncall_type"]
            and not integration["is_escalation_policy_flawed"]
        ):
            migrate_integration(integration, escalation_policies)
            print(TAB + format_integration(integration))

    if rulesets is not None:
        print("▶ Migrating event rules (global rulesets)...")
        for ruleset in rulesets:
            if not ruleset["flawed_escalation_policies"]:
                migrate_ruleset(ruleset, escalation_policies, services)
                print(TAB + format_ruleset(ruleset))

    if PAGERDUTY_MIGRATE_SERVICES:
        print("▶ Migrating services to Grafana's service model...")
        migrate_all_services(
            client, technical_services, business_services, dry_run=False
        )
    else:
        print("▶ Skipping service migration as PAGERDUTY_MIGRATE_SERVICES is false...")