package cmd

import (
	"bufio"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/spf13/cobra"
	"github.com/steveyegge/gastown/internal/claude"
	"github.com/steveyegge/gastown/internal/config"
	"github.com/steveyegge/gastown/internal/git"
	"github.com/steveyegge/gastown/internal/polecat"
	"github.com/steveyegge/gastown/internal/rig"
	"github.com/steveyegge/gastown/internal/style"
	"github.com/steveyegge/gastown/internal/tmux"
	"github.com/steveyegge/gastown/internal/workspace"
)

var (
	startAll             bool
	shutdownGraceful     bool
	shutdownWait         int
	shutdownAll          bool
	shutdownForce        bool
	shutdownYes          bool
	shutdownPolecatsOnly bool
	shutdownNuclear      bool
)

var startCmd = &cobra.Command{
	Use:     "start",
	GroupID: GroupServices,
	Short:   "Start Gas Town",
	Long: `Start Gas Town by launching the Deacon and Mayor.

The Deacon is the health-check orchestrator that monitors Mayor and Witnesses.
The Mayor is the global coordinator that dispatches work.

By default, other agents (Witnesses, Refineries) are started lazily as needed.
Use --all to start Witnesses and Refineries for all registered rigs immediately.

To stop Gas Town, use 'gt shutdown'.`,
	RunE: runStart,
}

var shutdownCmd = &cobra.Command{
	Use:     "shutdown",
	GroupID: GroupServices,
	Short:   "Shutdown Gas Town",
	Long: `Shutdown Gas Town by stopping agents and cleaning up polecats.

By default, preserves crew sessions (your persistent workspaces).
Prompts for confirmation before stopping.

After killing sessions, polecats are cleaned up:
  - Worktrees are removed
  - Polecat branches are deleted
  - Polecats with uncommitted work are SKIPPED (protected)

Shutdown levels (progressively more aggressive):
  (default)       - Stop infrastructure (Mayor, Deacon, Witnesses, Refineries, Polecats)
  --all           - Also stop crew sessions
  --polecats-only - Only stop polecats (leaves everything else running)

Use --force or --yes to skip confirmation prompt.
Use --graceful to allow agents time to save state before killing.
Use --nuclear to force cleanup even if polecats have uncommitted work (DANGER).`,
	RunE: runShutdown,
}

func init() {
	startCmd.Flags().BoolVarP(&startAll, "all", "a", false,
		"Also start Witnesses and Refineries for all rigs")

	shutdownCmd.Flags().BoolVarP(&shutdownGraceful, "graceful", "g", false,
		"Send ESC to agents and wait for them to handoff before killing")
	shutdownCmd.Flags().IntVarP(&shutdownWait, "wait", "w", 30,
		"Seconds to wait for graceful shutdown (default 30)")
	shutdownCmd.Flags().BoolVarP(&shutdownAll, "all", "a", false,
		"Also stop crew sessions (by default, crew is preserved)")
	shutdownCmd.Flags().BoolVarP(&shutdownForce, "force", "f", false,
		"Skip confirmation prompt (alias for --yes)")
	shutdownCmd.Flags().BoolVarP(&shutdownYes, "yes", "y", false,
		"Skip confirmation prompt")
	shutdownCmd.Flags().BoolVar(&shutdownPolecatsOnly, "polecats-only", false,
		"Only stop polecats (minimal shutdown)")
	shutdownCmd.Flags().BoolVar(&shutdownNuclear, "nuclear", false,
		"Force cleanup even if polecats have uncommitted work (DANGER: may lose work)")

	rootCmd.AddCommand(startCmd)
	rootCmd.AddCommand(shutdownCmd)
}

func runStart(cmd *cobra.Command, args []string) error {
	// Verify we're in a Gas Town workspace
	townRoot, err := workspace.FindFromCwdOrError()
	if err != nil {
		return fmt.Errorf("not in a Gas Town workspace: %w", err)
	}

	t := tmux.NewTmux()

	fmt.Printf("Starting Gas Town from %s\n\n", style.Dim.Render(townRoot))

	// Start Mayor first (so Deacon sees it as up)
	mayorRunning, _ := t.HasSession(MayorSessionName)
	if mayorRunning {
		fmt.Printf("  %s Mayor already running\n", style.Dim.Render("○"))
	} else {
		fmt.Printf("  %s Starting Mayor...\n", style.Bold.Render("→"))
		if err := startMayorSession(t); err != nil {
			return fmt.Errorf("starting Mayor: %w", err)
		}
		fmt.Printf("  %s Mayor started\n", style.Bold.Render("✓"))
	}

	// Start Deacon (health monitor)
	deaconRunning, _ := t.HasSession(DeaconSessionName)
	if deaconRunning {
		fmt.Printf("  %s Deacon already running\n", style.Dim.Render("○"))
	} else {
		fmt.Printf("  %s Starting Deacon...\n", style.Bold.Render("→"))
		if err := startDeaconSession(t); err != nil {
			return fmt.Errorf("starting Deacon: %w", err)
		}
		fmt.Printf("  %s Deacon started\n", style.Bold.Render("✓"))
	}

	// If --all, start witnesses and refineries for all rigs
	if startAll {
		fmt.Println()
		fmt.Println("Starting rig agents...")

		rigs, err := discoverAllRigs(townRoot)
		if err != nil {
			fmt.Printf("  %s Could not discover rigs: %v\n", style.Dim.Render("○"), err)
		} else {
			for _, r := range rigs {
				// Start Witness
				witnessSession := fmt.Sprintf("gt-%s-witness", r.Name)
				witnessRunning, _ := t.HasSession(witnessSession)
				if witnessRunning {
					fmt.Printf("  %s %s witness already running\n", style.Dim.Render("○"), r.Name)
				} else {
					created, err := ensureWitnessSession(r.Name, r)
					if err != nil {
						fmt.Printf("  %s %s witness failed: %v\n", style.Dim.Render("○"), r.Name, err)
					} else if created {
						fmt.Printf("  %s %s witness started\n", style.Bold.Render("✓"), r.Name)
					}
				}

				// Start Refinery
				refinerySession := fmt.Sprintf("gt-%s-refinery", r.Name)
				refineryRunning, _ := t.HasSession(refinerySession)
				if refineryRunning {
					fmt.Printf("  %s %s refinery already running\n", style.Dim.Render("○"), r.Name)
				} else {
					created, err := ensureRefinerySession(r.Name, r)
					if err != nil {
						fmt.Printf("  %s %s refinery failed: %v\n", style.Dim.Render("○"), r.Name, err)
					} else if created {
						fmt.Printf("  %s %s refinery started\n", style.Bold.Render("✓"), r.Name)
					}
				}
			}
		}
	}

	fmt.Println()
	fmt.Printf("%s Gas Town is running\n", style.Bold.Render("✓"))
	fmt.Println()
	fmt.Printf("  Attach to Mayor:  %s\n", style.Dim.Render("gt mayor attach"))
	fmt.Printf("  Attach to Deacon: %s\n", style.Dim.Render("gt deacon attach"))
	fmt.Printf("  Check status:     %s\n", style.Dim.Render("gt status"))

	return nil
}

// discoverAllRigs finds all rigs in the workspace.
func discoverAllRigs(townRoot string) ([]*rig.Rig, error) {
	rigsConfigPath := filepath.Join(townRoot, "mayor", "rigs.json")
	rigsConfig, err := config.LoadRigsConfig(rigsConfigPath)
	if err != nil {
		return nil, fmt.Errorf("loading rigs config: %w", err)
	}

	g := git.NewGit(townRoot)
	rigMgr := rig.NewManager(townRoot, rigsConfig, g)

	return rigMgr.DiscoverRigs()
}

// ensureRefinerySession creates a refinery tmux session if it doesn't exist.
// Returns true if a new session was created, false if it already existed.
func ensureRefinerySession(rigName string, r *rig.Rig) (bool, error) {
	t := tmux.NewTmux()
	sessionName := fmt.Sprintf("gt-%s-refinery", rigName)

	// Check if session already exists
	running, err := t.HasSession(sessionName)
	if err != nil {
		return false, fmt.Errorf("checking session: %w", err)
	}

	if running {
		return false, nil
	}

	// Working directory is the refinery's rig clone
	refineryRigDir := filepath.Join(r.Path, "refinery", "rig")
	if _, err := os.Stat(refineryRigDir); os.IsNotExist(err) {
		// Fall back to rig path if refinery/rig doesn't exist
		refineryRigDir = r.Path
	}

	// Ensure Claude settings exist (autonomous role needs mail in SessionStart)
	if err := claude.EnsureSettingsForRole(refineryRigDir, "refinery"); err != nil {
		return false, fmt.Errorf("ensuring Claude settings: %w", err)
	}

	// Create new tmux session
	if err := t.NewSession(sessionName, refineryRigDir); err != nil {
		return false, fmt.Errorf("creating session: %w", err)
	}

	// Set environment
	t.SetEnvironment(sessionName, "GT_ROLE", "refinery")
	t.SetEnvironment(sessionName, "GT_RIG", rigName)

	// Set beads environment
	beadsDir := filepath.Join(r.Path, "mayor", "rig", ".beads")
	t.SetEnvironment(sessionName, "BEADS_DIR", beadsDir)
	t.SetEnvironment(sessionName, "BEADS_NO_DAEMON", "1")
	t.SetEnvironment(sessionName, "BEADS_AGENT_NAME", fmt.Sprintf("%s/refinery", rigName))

	// Apply Gas Town theming
	theme := tmux.AssignTheme(rigName)
	_ = t.ConfigureGasTownSession(sessionName, theme, rigName, "refinery", "refinery")

	// Launch Claude in a respawn loop
	// Export GT_ROLE in the command since tmux SetEnvironment only affects new panes
	loopCmd := `export GT_ROLE=refinery && while true; do echo "🛢️ Starting Refinery for ` + rigName + `..."; claude --dangerously-skip-permissions; echo ""; echo "Refinery exited. Restarting in 2s... (Ctrl-C to stop)"; sleep 2; done`
	if err := t.SendKeysDelayed(sessionName, loopCmd, 200); err != nil {
		return false, fmt.Errorf("sending command: %w", err)
	}

	return true, nil
}

func runShutdown(cmd *cobra.Command, args []string) error {
	t := tmux.NewTmux()

	// Find workspace root for polecat cleanup
	townRoot, _ := workspace.FindFromCwd()

	// Collect sessions to show what will be stopped
	sessions, err := t.ListSessions()
	if err != nil {
		return fmt.Errorf("listing sessions: %w", err)
	}

	toStop, preserved := categorizeSessions(sessions)

	if len(toStop) == 0 {
		fmt.Printf("%s Gas Town was not running\n", style.Dim.Render("○"))
		return nil
	}

	// Show what will happen
	fmt.Println("Sessions to stop:")
	for _, sess := range toStop {
		fmt.Printf("  %s %s\n", style.Bold.Render("→"), sess)
	}
	if len(preserved) > 0 && !shutdownAll {
		fmt.Println()
		fmt.Println("Sessions preserved (crew):")
		for _, sess := range preserved {
			fmt.Printf("  %s %s\n", style.Dim.Render("○"), sess)
		}
	}
	fmt.Println()

	// Confirmation prompt
	if !shutdownYes && !shutdownForce {
		fmt.Printf("Proceed with shutdown? [y/N] ")
		reader := bufio.NewReader(os.Stdin)
		response, _ := reader.ReadString('\n')
		response = strings.TrimSpace(strings.ToLower(response))
		if response != "y" && response != "yes" {
			fmt.Println("Shutdown cancelled.")
			return nil
		}
	}

	if shutdownGraceful {
		return runGracefulShutdown(t, toStop, townRoot)
	}
	return runImmediateShutdown(t, toStop, townRoot)
}

// categorizeSessions splits sessions into those to stop and those to preserve.
func categorizeSessions(sessions []string) (toStop, preserved []string) {
	for _, sess := range sessions {
		if !strings.HasPrefix(sess, "gt-") {
			continue // Not a Gas Town session
		}

		// Check if it's a crew session (pattern: gt-<rig>-crew-<name>)
		isCrew := strings.Contains(sess, "-crew-")

		// Check if it's a polecat session (pattern: gt-<rig>-<name> where name is not crew/witness/refinery)
		isPolecat := false
		if !isCrew && sess != MayorSessionName && sess != DeaconSessionName {
			parts := strings.Split(sess, "-")
			if len(parts) >= 3 {
				role := parts[2]
				if role != "witness" && role != "refinery" && role != "crew" {
					isPolecat = true
				}
			}
		}

		// Decide based on flags
		if shutdownPolecatsOnly {
			// Only stop polecats
			if isPolecat {
				toStop = append(toStop, sess)
			} else {
				preserved = append(preserved, sess)
			}
		} else if shutdownAll {
			// Stop everything including crew
			toStop = append(toStop, sess)
		} else {
			// Default: preserve crew
			if isCrew {
				preserved = append(preserved, sess)
			} else {
				toStop = append(toStop, sess)
			}
		}
	}
	return
}

func runGracefulShutdown(t *tmux.Tmux, gtSessions []string, townRoot string) error {
	fmt.Printf("Graceful shutdown of Gas Town (waiting up to %ds)...\n\n", shutdownWait)

	// Phase 1: Send ESC to all agents to interrupt them
	fmt.Printf("Phase 1: Sending ESC to %d agent(s)...\n", len(gtSessions))
	for _, sess := range gtSessions {
		fmt.Printf("  %s Interrupting %s\n", style.Bold.Render("→"), sess)
		_ = t.SendKeysRaw(sess, "Escape")
	}

	// Phase 2: Send shutdown message asking agents to handoff
	fmt.Printf("\nPhase 2: Requesting handoff from agents...\n")
	shutdownMsg := "[SHUTDOWN] Gas Town is shutting down. Please save your state and update your handoff bead, then type /exit or wait to be terminated."
	for _, sess := range gtSessions {
		// Small delay then send the message
		time.Sleep(500 * time.Millisecond)
		_ = t.SendKeys(sess, shutdownMsg)
	}

	// Phase 3: Wait for agents to complete handoff
	fmt.Printf("\nPhase 3: Waiting %ds for agents to complete handoff...\n", shutdownWait)
	fmt.Printf("  %s\n", style.Dim.Render("(Press Ctrl-C to force immediate shutdown)"))

	// Wait with countdown
	for remaining := shutdownWait; remaining > 0; remaining -= 5 {
		if remaining < shutdownWait {
			fmt.Printf("  %s %ds remaining...\n", style.Dim.Render("⏳"), remaining)
		}
		sleepTime := 5
		if remaining < 5 {
			sleepTime = remaining
		}
		time.Sleep(time.Duration(sleepTime) * time.Second)
	}

	// Phase 4: Kill sessions in correct order
	fmt.Printf("\nPhase 4: Terminating sessions...\n")
	stopped := killSessionsInOrder(t, gtSessions)

	// Phase 5: Cleanup polecat worktrees and branches
	fmt.Printf("\nPhase 5: Cleaning up polecats...\n")
	if townRoot != "" {
		cleanupPolecats(townRoot)
	}

	fmt.Println()
	fmt.Printf("%s Graceful shutdown complete (%d sessions stopped)\n", style.Bold.Render("✓"), stopped)
	return nil
}

func runImmediateShutdown(t *tmux.Tmux, gtSessions []string, townRoot string) error {
	fmt.Println("Shutting down Gas Town...")

	stopped := killSessionsInOrder(t, gtSessions)

	// Cleanup polecat worktrees and branches
	if townRoot != "" {
		fmt.Println()
		fmt.Println("Cleaning up polecats...")
		cleanupPolecats(townRoot)
	}

	fmt.Println()
	fmt.Printf("%s Gas Town shutdown complete (%d sessions stopped)\n", style.Bold.Render("✓"), stopped)

	return nil
}

// killSessionsInOrder stops sessions in the correct order:
// 1. Deacon first (so it doesn't restart others)
// 2. Everything except Mayor
// 3. Mayor last
func killSessionsInOrder(t *tmux.Tmux, sessions []string) int {
	stopped := 0

	// Helper to check if session is in our list
	inList := func(sess string) bool {
		for _, s := range sessions {
			if s == sess {
				return true
			}
		}
		return false
	}

	// 1. Stop Deacon first
	if inList(DeaconSessionName) {
		if err := t.KillSession(DeaconSessionName); err == nil {
			fmt.Printf("  %s %s stopped\n", style.Bold.Render("✓"), DeaconSessionName)
			stopped++
		}
	}

	// 2. Stop others (except Mayor)
	for _, sess := range sessions {
		if sess == DeaconSessionName || sess == MayorSessionName {
			continue
		}
		if err := t.KillSession(sess); err == nil {
			fmt.Printf("  %s %s stopped\n", style.Bold.Render("✓"), sess)
			stopped++
		}
	}

	// 3. Stop Mayor last
	if inList(MayorSessionName) {
		if err := t.KillSession(MayorSessionName); err == nil {
			fmt.Printf("  %s %s stopped\n", style.Bold.Render("✓"), MayorSessionName)
			stopped++
		}
	}

	return stopped
}

// cleanupPolecats removes polecat worktrees and branches for all rigs.
// It refuses to clean up polecats with uncommitted work unless --nuclear is set.
func cleanupPolecats(townRoot string) {
	// Load rigs config
	rigsConfigPath := filepath.Join(townRoot, "mayor", "rigs.json")
	rigsConfig, err := config.LoadRigsConfig(rigsConfigPath)
	if err != nil {
		fmt.Printf("  %s Could not load rigs config: %v\n", style.Dim.Render("○"), err)
		return
	}

	g := git.NewGit(townRoot)
	rigMgr := rig.NewManager(townRoot, rigsConfig, g)

	// Discover all rigs
	rigs, err := rigMgr.DiscoverRigs()
	if err != nil {
		fmt.Printf("  %s Could not discover rigs: %v\n", style.Dim.Render("○"), err)
		return
	}

	totalCleaned := 0
	totalSkipped := 0
	var uncommittedPolecats []string

	for _, r := range rigs {
		polecatGit := git.NewGit(r.Path)
		polecatMgr := polecat.NewManager(r, polecatGit)

		polecats, err := polecatMgr.List()
		if err != nil {
			continue
		}

		for _, p := range polecats {
			// Check for uncommitted work
			pGit := git.NewGit(p.ClonePath)
			status, err := pGit.CheckUncommittedWork()
			if err != nil {
				// Can't check, be safe and skip unless nuclear
				if !shutdownNuclear {
					fmt.Printf("  %s %s/%s: could not check status, skipping\n",
						style.Dim.Render("○"), r.Name, p.Name)
					totalSkipped++
					continue
				}
			} else if !status.Clean() {
				// Has uncommitted work
				if !shutdownNuclear {
					uncommittedPolecats = append(uncommittedPolecats,
						fmt.Sprintf("%s/%s (%s)", r.Name, p.Name, status.String()))
					totalSkipped++
					continue
				}
				// Nuclear mode: warn but proceed
				fmt.Printf("  %s %s/%s: NUCLEAR - removing despite %s\n",
					style.Bold.Render("⚠"), r.Name, p.Name, status.String())
			}

			// Clean: remove worktree and branch
			if err := polecatMgr.RemoveWithOptions(p.Name, true, shutdownNuclear); err != nil {
				fmt.Printf("  %s %s/%s: cleanup failed: %v\n",
					style.Dim.Render("○"), r.Name, p.Name, err)
				totalSkipped++
				continue
			}

			// Delete the polecat branch from mayor's clone
			branchName := fmt.Sprintf("polecat/%s", p.Name)
			mayorPath := filepath.Join(r.Path, "mayor", "rig")
			mayorGit := git.NewGit(mayorPath)
			_ = mayorGit.DeleteBranch(branchName, true) // Ignore errors

			fmt.Printf("  %s %s/%s: cleaned up\n", style.Bold.Render("✓"), r.Name, p.Name)
			totalCleaned++
		}
	}

	// Summary
	if len(uncommittedPolecats) > 0 {
		fmt.Println()
		fmt.Printf("  %s Polecats with uncommitted work (use --nuclear to force):\n",
			style.Bold.Render("⚠"))
		for _, pc := range uncommittedPolecats {
			fmt.Printf("    • %s\n", pc)
		}
	}

	if totalCleaned > 0 || totalSkipped > 0 {
		fmt.Printf("  Cleaned: %d, Skipped: %d\n", totalCleaned, totalSkipped)
	} else {
		fmt.Printf("  %s No polecats to clean up\n", style.Dim.Render("○"))
	}
}