package cmd

import (
	"encoding/json"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"

	"github.com/spf13/cobra"
	"github.com/warrenronsiek/ctask/internal/config"
	"github.com/warrenronsiek/ctask/internal/workspace"
)

var doctorCmd = &cobra.Command{
	Use:          "doctor",
	Short:        "Verify ctask setup and diagnose configuration problems",
	Args:         cobra.NoArgs,
	SilenceUsage: true,
	RunE:         runDoctor,
}

func init() {
	rootCmd.AddCommand(doctorCmd)
}

func runDoctor(cmd *cobra.Command, args []string) error {
	passed := 0
	failed := 0

	// Check 1: Workspace root exists and is writable
	root := config.ResolveRoot()
	if info, err := os.Stat(root); err == nil && info.IsDir() {
		// Test writability by creating a temp file
		testFile := filepath.Join(root, ".ctask-doctor-test")
		if err := os.WriteFile(testFile, []byte("test"), 0644); err == nil {
			os.Remove(testFile)
			fmt.Printf("  [PASS] Workspace root exists: %s\n", root)
			passed++
		} else {
			fmt.Printf("  [FAIL] Workspace root not writable: %s\n", root)
			fmt.Printf("         Fix: check permissions on %s\n", root)
			failed++
		}
	} else {
		fmt.Printf("  [FAIL] Workspace root not found: %s\n", root)
		fmt.Printf("         Fix: create it with: mkdir %s\n", root)
		failed++
	}

	// Check 2: Default agent on PATH
	agent := config.ResolveAgent()
	if _, err := exec.LookPath(agent); err == nil {
		fmt.Printf("  [PASS] Default agent found: %s\n", agent)
		passed++
	} else {
		fmt.Printf("  [FAIL] Agent command not found: %s\n", agent)
		fmt.Printf("         Fix: install it or set CTASK_AGENT to a different command\n")
		failed++
	}

	// Check 3: Status line helper exists
	// The canonical location is next to the ctask binary in GOPATH/bin,
	// or on Unix in ~/.local/bin. We check both the bash and powershell variants.
	statusLineFound := false
	statusLinePath := ""

	// Determine expected locations based on platform
	var searchPaths []string
	home, _ := os.UserHomeDir()
	gopath := os.Getenv("GOPATH")
	if gopath == "" {
		gopath = filepath.Join(home, "go")
	}
	gopathBin := filepath.Join(gopath, "bin")

	if runtime.GOOS == "windows" {
		searchPaths = []string{
			filepath.Join(gopathBin, "ctask-statusline.sh"),
			filepath.Join(gopathBin, "ctask-statusline.ps1"),
		}
	} else {
		searchPaths = []string{
			filepath.Join(home, ".local", "bin", "ctask-statusline.sh"),
			filepath.Join(gopathBin, "ctask-statusline.sh"),
			"/usr/local/bin/ctask-statusline.sh",
		}
	}

	for _, p := range searchPaths {
		if _, err := os.Stat(p); err == nil {
			statusLineFound = true
			statusLinePath = p
			break
		}
	}

	if statusLineFound {
		fmt.Printf("  [PASS] Status line helper found: %s\n", statusLinePath)
		passed++
	} else {
		fmt.Printf("  [FAIL] Status line helper not found\n")
		fmt.Printf("         Fix: copy ctask-statusline.sh to %s\n", searchPaths[0])
		failed++
	}

	// Check 4: Claude Code status line configured
	claudeSettingsPath := filepath.Join(home, ".claude", "settings.json")
	statusLineConfigured := false

	if data, err := os.ReadFile(claudeSettingsPath); err == nil {
		var settings map[string]interface{}
		if err := json.Unmarshal(data, &settings); err == nil {
			if sl, ok := settings["statusLine"].(map[string]interface{}); ok {
				slType, _ := sl["type"].(string)
				slCmd, _ := sl["command"].(string)
				if slType == "command" && slCmd != "" {
					// Check if the referenced file in the command exists
					// Extract the file path from the command (last argument typically)
					statusLineConfigured = true
					fmt.Printf("  [PASS] Claude Code status line configured\n")
					passed++
				}
			}
		}
	}

	if !statusLineConfigured {
		fmt.Printf("  [FAIL] Claude Code status line not configured or misconfigured\n")
		fmt.Printf("         Fix: add to %s:\n", claudeSettingsPath)
		if runtime.GOOS == "windows" {
			fmt.Printf("         \"statusLine\": {\"type\": \"command\", \"command\": \"bash /c/Users/<you>/go/bin/ctask-statusline.sh\"}\n")
		} else {
			fmt.Printf("         \"statusLine\": {\"type\": \"command\", \"command\": \"bash ~/.local/bin/ctask-statusline.sh\"}\n")
		}
		failed++
	}

	// Check 5: Workspace root has workspaces
	results, err := workspace.ListWorkspaces(root, workspace.ListOpts{
		IncludeArchived: true,
		Limit:           0, // no limit
	})
	if err == nil && len(results) > 0 {
		activeCount := 0
		archivedCount := 0
		for _, r := range results {
			if r.Meta.Status == "archived" {
				archivedCount++
			} else {
				activeCount++
			}
		}
		fmt.Printf("  [PASS] Workspaces found: %d tasks", len(results))
		if archivedCount > 0 {
			fmt.Printf(" (%d archived)", archivedCount)
		}
		fmt.Println()
		passed++
	} else {
		fmt.Printf("  [FAIL] No workspaces found\n")
		fmt.Printf("         Fix: create one with: ctask new \"my first task\"\n")
		failed++
	}

	// Summary
	fmt.Println()
	fmt.Printf("%d checks passed, %d failed\n", passed, failed)

	if failed > 0 {
		return fmt.Errorf("%d checks failed", failed)
	}
	return nil
}