package commands

import (
	"bytes"
	"encoding/json"
	"fmt"
	"strings"

	"git.hangman-lab.top/zhi/HarborForge.Cli/internal/client"
	"git.hangman-lab.top/zhi/HarborForge.Cli/internal/config"
	"git.hangman-lab.top/zhi/HarborForge.Cli/internal/output"
)

// roleResponse matches the backend role list schema.
type roleResponse struct {
	ID            int    `json:"id"`
	Name          string `json:"name"`
	Description   string `json:"description"`
	IsGlobal      bool   `json:"is_global"`
	PermissionIDs []int  `json:"permission_ids"`
	CreatedAt     string `json:"created_at"`
}

// roleDetailResponse matches the backend role detail schema.
type roleDetailResponse struct {
	ID          int                  `json:"id"`
	Name        string               `json:"name"`
	Description string               `json:"description"`
	IsGlobal    bool                 `json:"is_global"`
	Permissions []permissionResponse `json:"permissions"`
	CreatedAt   string               `json:"created_at"`
}

// permissionResponse matches the backend permission schema.
type permissionResponse struct {
	ID          int    `json:"id"`
	Name        string `json:"name"`
	Description string `json:"description"`
	Category    string `json:"category"`
}

func loadRoleClient(tokenFlag string) (*client.Client, error) {
	token := ResolveToken(tokenFlag)
	cfg, err := config.Load()
	if err != nil {
		return nil, fmt.Errorf("config error: %w", err)
	}
	return client.New(cfg.BaseURL, token), nil
}

func fetchRoles(c *client.Client) ([]roleResponse, error) {
	data, err := c.Get("/roles")
	if err != nil {
		return nil, err
	}
	var roles []roleResponse
	if err := json.Unmarshal(data, &roles); err != nil {
		return nil, fmt.Errorf("cannot parse role list: %w", err)
	}
	return roles, nil
}

func fetchPermissions(c *client.Client) ([]permissionResponse, error) {
	data, err := c.Get("/roles/permissions")
	if err != nil {
		return nil, err
	}
	var perms []permissionResponse
	if err := json.Unmarshal(data, &perms); err != nil {
		return nil, fmt.Errorf("cannot parse permission list: %w", err)
	}
	return perms, nil
}

func findRoleByName(c *client.Client, roleName string) (*roleResponse, error) {
	roles, err := fetchRoles(c)
	if err != nil {
		return nil, err
	}
	for _, r := range roles {
		if r.Name == roleName {
			role := r
			return &role, nil
		}
	}
	return nil, fmt.Errorf("role not found: %s", roleName)
}

func fetchRoleDetailByName(c *client.Client, roleName string) (*roleDetailResponse, error) {
	role, err := findRoleByName(c, roleName)
	if err != nil {
		return nil, err
	}
	data, err := c.Get(fmt.Sprintf("/roles/%d", role.ID))
	if err != nil {
		return nil, err
	}
	var detail roleDetailResponse
	if err := json.Unmarshal(data, &detail); err != nil {
		return nil, fmt.Errorf("cannot parse role detail: %w", err)
	}
	return &detail, nil
}

func resolvePermissionIDs(c *client.Client, names []string) ([]int, error) {
	perms, err := fetchPermissions(c)
	if err != nil {
		return nil, err
	}
	byName := make(map[string]int, len(perms))
	for _, p := range perms {
		byName[p.Name] = p.ID
	}
	ids := make([]int, 0, len(names))
	seen := map[int]struct{}{}
	var missing []string
	for _, name := range names {
		id, ok := byName[name]
		if !ok {
			missing = append(missing, name)
			continue
		}
		if _, exists := seen[id]; exists {
			continue
		}
		seen[id] = struct{}{}
		ids = append(ids, id)
	}
	if len(missing) > 0 {
		return nil, fmt.Errorf("unknown permission(s): %s", strings.Join(missing, ", "))
	}
	return ids, nil
}

func replaceRolePermissions(c *client.Client, roleID int, permissionIDs []int) error {
	payload := map[string]interface{}{
		"permission_ids": permissionIDs,
	}
	body, err := json.Marshal(payload)
	if err != nil {
		return fmt.Errorf("cannot marshal payload: %w", err)
	}
	_, err = c.Post(fmt.Sprintf("/roles/%d/permissions", roleID), bytes.NewReader(body))
	return err
}

// RunRoleList implements `hf role list`.
func RunRoleList(tokenFlag string) {
	c, err := loadRoleClient(tokenFlag)
	if err != nil {
		output.Errorf("%v", err)
	}
	data, err := c.Get("/roles")
	if err != nil {
		output.Errorf("failed to list roles: %v", err)
	}

	if output.JSONMode {
		var raw json.RawMessage
		if err := json.Unmarshal(data, &raw); err != nil {
			output.Errorf("invalid JSON response: %v", err)
		}
		output.PrintJSON(raw)
		return
	}

	var roles []roleResponse
	if err := json.Unmarshal(data, &roles); err != nil {
		output.Errorf("cannot parse role list: %v", err)
	}

	headers := []string{"NAME", "DESCRIPTION", "GLOBAL", "PERM IDS"}
	var rows [][]string
	for _, r := range roles {
		global := ""
		if r.IsGlobal {
			global = "yes"
		}
		permIDs := ""
		if len(r.PermissionIDs) > 0 {
			parts := make([]string, 0, len(r.PermissionIDs))
			for _, id := range r.PermissionIDs {
				parts = append(parts, fmt.Sprintf("%d", id))
			}
			permIDs = strings.Join(parts, ", ")
		}
		rows = append(rows, []string{r.Name, r.Description, global, permIDs})
	}
	output.PrintTable(headers, rows)
}

// RunRoleGet implements `hf role get <role-name>`.
func RunRoleGet(roleName, tokenFlag string) {
	c, err := loadRoleClient(tokenFlag)
	if err != nil {
		output.Errorf("%v", err)
	}
	role, err := findRoleByName(c, roleName)
	if err != nil {
		output.Errorf("failed to get role: %v", err)
	}
	data, err := c.Get(fmt.Sprintf("/roles/%d", role.ID))
	if err != nil {
		output.Errorf("failed to get role: %v", err)
	}

	if output.JSONMode {
		var raw json.RawMessage
		if err := json.Unmarshal(data, &raw); err != nil {
			output.Errorf("invalid JSON response: %v", err)
		}
		output.PrintJSON(raw)
		return
	}

	var r roleDetailResponse
	if err := json.Unmarshal(data, &r); err != nil {
		output.Errorf("cannot parse role: %v", err)
	}

	global := "no"
	if r.IsGlobal {
		global = "yes"
	}
	perms := "(none)"
	if len(r.Permissions) > 0 {
		names := make([]string, 0, len(r.Permissions))
		for _, p := range r.Permissions {
			names = append(names, p.Name)
		}
		perms = strings.Join(names, ", ")
	}
	output.PrintKeyValue(
		"name", r.Name,
		"description", r.Description,
		"global", global,
		"permissions", perms,
	)
}

// RunRoleCreate implements `hf role create`.
func RunRoleCreate(name, desc string, global bool, tokenFlag string) {
	c, err := loadRoleClient(tokenFlag)
	if err != nil {
		output.Errorf("%v", err)
	}
	if name == "" {
		output.Error("usage: hf role create --name <role-name>")
	}

	payload := map[string]interface{}{
		"name": name,
	}
	if desc != "" {
		payload["description"] = desc
	}
	if global {
		payload["is_global"] = true
	}

	body, err := json.Marshal(payload)
	if err != nil {
		output.Errorf("cannot marshal payload: %v", err)
	}

	data, err := c.Post("/roles", bytes.NewReader(body))
	if err != nil {
		output.Errorf("failed to create role: %v", err)
	}

	if output.JSONMode {
		var raw json.RawMessage
		if err := json.Unmarshal(data, &raw); err != nil {
			output.Errorf("invalid JSON response: %v", err)
		}
		output.PrintJSON(raw)
		return
	}

	fmt.Printf("role created: %s\n", name)
}

// RunRoleUpdate implements `hf role update <role-name>`.
func RunRoleUpdate(roleName string, args []string, tokenFlag string) {
	c, err := loadRoleClient(tokenFlag)
	if err != nil {
		output.Errorf("%v", err)
	}
	role, err := findRoleByName(c, roleName)
	if err != nil {
		output.Errorf("failed to update role: %v", err)
	}

	payload := make(map[string]interface{})
	for i := 0; i < len(args); i++ {
		switch args[i] {
		case "--desc":
			if i+1 >= len(args) {
				output.Error("--desc requires a value")
			}
			i++
			payload["description"] = args[i]
		default:
			output.Errorf("unknown flag: %s", args[i])
		}
	}

	if len(payload) == 0 {
		output.Error("nothing to update — provide at least one flag")
	}

	body, err := json.Marshal(payload)
	if err != nil {
		output.Errorf("cannot marshal payload: %v", err)
	}

	_, err = c.Patch(fmt.Sprintf("/roles/%d", role.ID), bytes.NewReader(body))
	if err != nil {
		output.Errorf("failed to update role: %v", err)
	}

	fmt.Printf("role updated: %s\n", roleName)
}

// RunRoleDelete implements `hf role delete <role-name>`.
func RunRoleDelete(roleName, tokenFlag string) {
	c, err := loadRoleClient(tokenFlag)
	if err != nil {
		output.Errorf("%v", err)
	}
	role, err := findRoleByName(c, roleName)
	if err != nil {
		output.Errorf("failed to delete role: %v", err)
	}
	_, err = c.Delete(fmt.Sprintf("/roles/%d", role.ID))
	if err != nil {
		output.Errorf("failed to delete role: %v", err)
	}
	fmt.Printf("role deleted: %s\n", roleName)
}

// RunRoleSetPermissions implements `hf role set-permissions <role-name> --permission <perm> [...]`.
func RunRoleSetPermissions(roleName string, permissions []string, tokenFlag string) {
	c, err := loadRoleClient(tokenFlag)
	if err != nil {
		output.Errorf("%v", err)
	}
	if len(permissions) == 0 {
		output.Error("usage: hf role set-permissions <role-name> --permission <perm> [--permission <perm> ...]")
	}
	role, err := findRoleByName(c, roleName)
	if err != nil {
		output.Errorf("failed to set permissions: %v", err)
	}
	permissionIDs, err := resolvePermissionIDs(c, permissions)
	if err != nil {
		output.Errorf("failed to set permissions: %v", err)
	}
	if err := replaceRolePermissions(c, role.ID, permissionIDs); err != nil {
		output.Errorf("failed to set permissions: %v", err)
	}

	fmt.Printf("permissions set for role %s: %s\n", roleName, strings.Join(permissions, ", "))
}

// RunRoleAddPermissions implements `hf role add-permissions <role-name> --permission <perm> [...]`.
func RunRoleAddPermissions(roleName string, permissions []string, tokenFlag string) {
	c, err := loadRoleClient(tokenFlag)
	if err != nil {
		output.Errorf("%v", err)
	}
	if len(permissions) == 0 {
		output.Error("usage: hf role add-permissions <role-name> --permission <perm> [--permission <perm> ...]")
	}
	role, err := findRoleByName(c, roleName)
	if err != nil {
		output.Errorf("failed to add permissions: %v", err)
	}
	detail, err := fetchRoleDetailByName(c, roleName)
	if err != nil {
		output.Errorf("failed to add permissions: %v", err)
	}
	currentIDs := make([]int, 0, len(detail.Permissions))
	seen := map[int]struct{}{}
	for _, p := range detail.Permissions {
		seen[p.ID] = struct{}{}
		currentIDs = append(currentIDs, p.ID)
	}
	newIDs, err := resolvePermissionIDs(c, permissions)
	if err != nil {
		output.Errorf("failed to add permissions: %v", err)
	}
	for _, id := range newIDs {
		if _, ok := seen[id]; ok {
			continue
		}
		seen[id] = struct{}{}
		currentIDs = append(currentIDs, id)
	}
	if err := replaceRolePermissions(c, role.ID, currentIDs); err != nil {
		output.Errorf("failed to add permissions: %v", err)
	}

	fmt.Printf("permissions added to role %s: %s\n", roleName, strings.Join(permissions, ", "))
}

// RunRoleRemovePermissions implements `hf role remove-permissions <role-name> --permission <perm> [...]`.
func RunRoleRemovePermissions(roleName string, permissions []string, tokenFlag string) {
	c, err := loadRoleClient(tokenFlag)
	if err != nil {
		output.Errorf("%v", err)
	}
	if len(permissions) == 0 {
		output.Error("usage: hf role remove-permissions <role-name> --permission <perm> [--permission <perm> ...]")
	}
	role, err := findRoleByName(c, roleName)
	if err != nil {
		output.Errorf("failed to remove permissions: %v", err)
	}
	detail, err := fetchRoleDetailByName(c, roleName)
	if err != nil {
		output.Errorf("failed to remove permissions: %v", err)
	}
	removeIDs, err := resolvePermissionIDs(c, permissions)
	if err != nil {
		output.Errorf("failed to remove permissions: %v", err)
	}
	removeSet := map[int]struct{}{}
	for _, id := range removeIDs {
		removeSet[id] = struct{}{}
	}
	remaining := make([]int, 0, len(detail.Permissions))
	for _, p := range detail.Permissions {
		if _, ok := removeSet[p.ID]; ok {
			continue
		}
		remaining = append(remaining, p.ID)
	}
	if err := replaceRolePermissions(c, role.ID, remaining); err != nil {
		output.Errorf("failed to remove permissions: %v", err)
	}

	fmt.Printf("permissions removed from role %s: %s\n", roleName, strings.Join(permissions, ", "))
}

// RunPermissionList implements `hf permission list`.
func RunPermissionList(tokenFlag string) {
	c, err := loadRoleClient(tokenFlag)
	if err != nil {
		output.Errorf("%v", err)
	}
	data, err := c.Get("/roles/permissions")
	if err != nil {
		output.Errorf("failed to list permissions: %v", err)
	}

	if output.JSONMode {
		var raw json.RawMessage
		if err := json.Unmarshal(data, &raw); err != nil {
			output.Errorf("invalid JSON response: %v", err)
		}
		output.PrintJSON(raw)
		return
	}

	var perms []permissionResponse
	if err := json.Unmarshal(data, &perms); err != nil {
		output.Errorf("cannot parse permission list: %v", err)
	}

	headers := []string{"ID", "NAME", "CATEGORY", "DESCRIPTION"}
	var rows [][]string
	for _, p := range perms {
		rows = append(rows, []string{fmt.Sprintf("%d", p.ID), p.Name, p.Category, p.Description})
	}
	output.PrintTable(headers, rows)
}