"""Execute and rollback command implementations."""

from __future__ import annotations

from pathlib import Path
from typing import Optional

import click

from vlm.context import CLIContext
from vlm.executor import ExecutionEngine
from vlm.plan_render import preferred_plan_summary
from vlm.planner import load_plan
from vlm.state import StateManager


def _validate_plan_structure(execution_plan) -> list[str]:
    """Validate source/destination paths for move/rename operations."""
    validation_errors: list[str] = []

    for operation in execution_plan.operations:
        if operation.operation_type in ("move", "rename"):
            if not operation.source_path.exists():
                validation_errors.append(f"Source file does not exist: {operation.source_path}")
            elif not operation.source_path.is_file():
                validation_errors.append(f"Source path is not a file: {operation.source_path}")

    for operation in execution_plan.operations:
        if operation.operation_type in ("move", "rename") and operation.destination_path:
            dest_dir = operation.destination_path.parent
            if not dest_dir.exists() and not dest_dir.parent.exists():
                validation_errors.append(f"Cannot create destination directory (parent missing): {dest_dir}")

    return validation_errors


def execute_cmd(
    ctx: CLIContext,
    plan: Path,
    confirm: bool,
    yes: bool,
    verbose_ops: bool,
    preserve_directories: bool,
    safe_mode: bool,
    require_review: bool = False,
    review_csv: Path | None = None,
) -> None:
    """Execute an execution plan in dry-run or execute mode."""
    config = ctx.config
    logger = ctx.logger
    mode = "execute" if confirm else "dry-run"

    click.echo(f"Loading execution plan from: {plan}")
    click.echo()

    execution_plan = load_plan(plan)

    if require_review and confirm:
        from vlm.plan_review import check_review_requirements

        csv_path = review_csv or plan.parent / "plan_manual_review.csv"
        review_errors = check_review_requirements(execution_plan, plan, csv_path)
        if review_errors:
            formatted = "\n".join(f"  - {e}" for e in review_errors)
            raise ValueError(f"REVIEW REQUIRED BEFORE EXECUTE:\n{formatted}")

    if preserve_directories:
        click.echo("Directory preservation is enabled (plan metadata/operations will be honored).")
        click.echo()

    if safe_mode:
        click.echo("Safe mode enabled - validating plan for directory preservation...")
        validation_snapshot = execution_plan.metadata.get("validation_snapshot", {})
        if not isinstance(validation_snapshot, dict):
            validation_snapshot = {}
        emptied_dirs = validation_snapshot.get("emptied_directories", execution_plan.metadata.get("emptied_directories", []))
        if emptied_dirs:
            raise ValueError(
                "SAFE MODE VIOLATION: plan would empty directories. "
                "Regenerate/adjust the plan to preserve directory structure."
            )
        click.echo("Safe mode validation passed - no directories would be destroyed")
        click.echo()

    click.echo("Validating directory structure...")
    validation_errors = _validate_plan_structure(execution_plan)
    if validation_errors:
        formatted = "\n".join(f"  - {error}" for error in validation_errors[:10])
        if len(validation_errors) > 10:
            formatted += f"\n  ... and {len(validation_errors) - 10} more errors"
        raise ValueError(f"DIRECTORY STRUCTURE VALIDATION FAILED:\n{formatted}")

    click.echo("Directory structure validation passed")
    click.echo()

    click.echo(f"Execution plan loaded: {execution_plan.plan_id}")
    click.echo(f"Created at: {execution_plan.created_at}")
    click.echo(f"Total operations: {len(execution_plan.operations)}")

    plan_summary = preferred_plan_summary(execution_plan)
    if plan_summary:
        click.echo()
        click.echo(plan_summary)
    click.echo()

    if mode == "dry-run":
        click.echo("DRY-RUN MODE - No files will be modified")
        click.echo("Use --confirm to actually execute operations")
    else:
        click.echo("EXECUTE MODE - Files will be modified")
        click.echo()
        if not yes and not click.confirm("Are you sure you want to proceed?"):
            click.echo("Execution cancelled.")
            return
        if yes:
            click.echo("Auto-approved via --yes flag")

    click.echo()
    click.echo(f"Executing {len(execution_plan.operations)} operations...")
    click.echo()

    state_path = Path.home() / ".vlm" / "state.json"
    state_manager = StateManager(state_path)

    engine = ExecutionEngine(
        logger=logger,
        config=config,
        verbose_operations=verbose_ops,
        state_manager=state_manager,
    )
    results, summary, rollback_log = engine.execute_plan(
        execution_plan,
        mode=mode,
        confirmed=confirm,
    )

    if mode == "dry-run":
        click.echo("Sample operations (dry-run):")
        for i, result in enumerate(results[:5]):
            op = result.operation
            if op.operation_type != "no-op":
                click.echo(f"  [{i + 1}] {op.operation_type}: {op.source_path.name}")
                if op.destination_path:
                    click.echo(f"      -> {op.destination_path}")
        if len(results) > 5:
            click.echo(f"  ... and {len(results) - 5} more operations")
    else:
        for i, result in enumerate(results):
            op = result.operation
            if op.operation_type != "no-op" and not op.has_conflict:
                status = "OK" if result.success else "FAIL"
                click.echo(f"  [{i + 1}/{len(results)}] {status} {op.operation_type}: {op.source_path.name}")
                if result.error_message:
                    click.echo(f"      Error: {result.error_message}")

    click.echo()
    click.echo("=" * 60)
    click.echo(f"Execution Summary ({mode} mode)")
    click.echo("=" * 60)
    click.echo(f"  Total operations: {summary['total']}")
    click.echo(f"  Successful: {summary['successful']}")
    click.echo(f"  Failed: {summary['failed']}")
    click.echo(f"  Skipped: {summary['skipped']}")
    click.echo()

    if mode == "execute" and rollback_log:
        rollback_dir = Path.home() / ".vlm" / "rollback"
        rollback_dir.mkdir(parents=True, exist_ok=True)
        rollback_path = rollback_dir / f"rollback_{rollback_log.log_id}.json"
        engine.save_rollback_log(rollback_log, rollback_path)

        click.echo(f"Rollback log saved to: {rollback_path}")
        click.echo()
        click.echo("To undo these operations, run:")
        click.echo(f"  vlm rollback --log {rollback_path}")
        click.echo()

    if mode == "dry-run":
        click.echo("Dry-run complete! No files were modified.")
        click.echo("Review the operations above and use --confirm to execute.")
    elif summary["failed"] > 0:
        click.echo(f"Execution completed with {summary['failed']} failures.")
        click.echo("Check the log file for details.")
    else:
        click.echo("Execution completed successfully!")

    logger.info(
        "Execution completed in %s mode: %s successful, %s failed, %s skipped",
        mode,
        summary["successful"],
        summary["failed"],
        summary["skipped"],
    )


def rollback_cmd(ctx: CLIContext, log: Optional[Path]) -> None:
    """Rollback a prior execution from rollback log."""
    config = ctx.config
    logger = ctx.logger

    if log is None:
        rollback_dir = Path.home() / ".vlm" / "rollback"
        if not rollback_dir.exists():
            raise FileNotFoundError(f"No rollback logs found. Rollback directory does not exist: {rollback_dir}")
        rollback_logs = sorted(
            rollback_dir.glob("rollback_*.json"), key=lambda p: p.stat().st_mtime, reverse=True
        )
        if not rollback_logs:
            raise FileNotFoundError(f"No rollback logs found. No rollback_*.json files in: {rollback_dir}")
        log = rollback_logs[0]

    click.echo(f"Loading rollback log: {log}")

    engine = ExecutionEngine(logger=logger, config=config)
    rollback_log = engine.load_rollback_log(log)

    click.echo(f"Rollback log loaded: {rollback_log.log_id}")
    click.echo(f"Plan ID: {rollback_log.execution_plan_id}")
    click.echo(f"Executed at: {rollback_log.executed_at}")
    click.echo(f"Operations to rollback: {len(rollback_log.operations)}")
    click.echo()

    if not click.confirm("Proceed with rollback?"):
        click.echo("Rollback cancelled.")
        return

    click.echo(f"Rolling back {len(rollback_log.operations)} operations...")
    click.echo()
    click.echo("Performing rollback...")
    rollback_results, rollback_summary = engine.rollback(rollback_log)

    click.echo()
    click.echo("Rollback Summary")
    click.echo("=" * 60)
    click.echo(f"  Total operations: {rollback_summary['total']}")
    click.echo(f"  Successful: {rollback_summary['successful']}")
    click.echo(f"  Failed: {rollback_summary['failed']}")
    click.echo(f"  Skipped: {rollback_summary['skipped']}")
    click.echo()

    if rollback_summary["failed"] > 0:
        click.echo("Failed operations:")
        for result in rollback_results:
            if not result.success:
                op = result.operation
                click.echo(f"  - {op.operation_type}: {op.source_path}")
                if result.error_message:
                    click.echo(f"    Error: {result.error_message}")
        click.echo()

    if rollback_summary["failed"] == 0:
        click.echo("Rollback completed successfully!")
    else:
        click.echo(f"Rollback completed with {rollback_summary['failed']} failures.")

    logger.info(
        "Rollback completed: %s successful, %s failed",
        rollback_summary["successful"],
        rollback_summary["failed"],
    )